Masahiko Yamada, Solid State Physics (ISSP), University of Tokyo
Crystalline spin-orbital liquids with an emergent SU(4) symmetry
Dr. Sarah King, Fritz Haber Institute of the Max Planck Society
Tracing the Dynamics of Interfacial Electronic Excited States from Femtoseconds to SecondsInterfacial electronic states determine the energy level alignment, charge transfer, and reactivity between two materials or phases of matter. For many interfaces and materials the excited states are more crucial to the functionality of the interface than the ground electronic states, such as in batteries, solar cells, or heterogeneous catalysts. A complete understanding of interfacial excited states requires knowledge of their lifetimes, dynamics, and reactivity on the relevant timescales, ranging from femtoseconds to seconds. I will discuss my work on two exemplary cases of the dynamics of interfacial electronic states: the formation of a small polaron at the dimethyl sulfoxide (DMSO)/metal interface and the reactivity of an electronic state at the amorphous solid water/vacuum interface, both investigated using time- and angle-resolved two-photon photoemission. DMSO is a common solvent used in battery electrolytes, and the experiments show a small polaron is formed on an ultrafast timescale via dynamic localization from a delocalized electronic state near the metal interface. Such insights are relevant for understanding the mechanism of electron localization at electrolyte/electrode interfaces. At the amorphous solid water/vacuum interface, a surface-bound electron that is formed via the conduction band of water is observed with a lifetime of tens of seconds. This electron undergoes a two-electron reaction with water, splitting water and producing hydroxide anions on the vacuum interface, with relevance to astrochemistry. These two different interfaces demonstrate how an understanding of excited state dynamics provides a unique insight into material interfaces and properties.
Physics with A Bang! Holiday Lecture and JFI Open HouseStudents, families, teachers and especially the curious are invited to attend our annual Holiday Lecture and Open House. See fast, loud, surprising and beautiful physics demos performed by Profs. Heinrich Jaeger and Sidney Nagel. Talk to scientists about their latest discoveries. Participate in hands-on activities related to their research.
Saturday, December 9th, 2017
Kersten Physics Teaching Center
5720 S. Ellis Ave., Chicago, IL
Lecture repeated at 11am and 2pm
Open House and Demo Alley from 12pm-4pm
Lab Tours in the afternoon
View the Live Stream of the 11am Show
View the Live Stream of the 2pm Show
See archived shows on our YouTube Channel
Doors for the Lectures open 30 minutes before each show. Admission to this event is free. Please note: there will be no online registrations, and will be a first to arrive, first ticketed event. We do not guarantee availibility of seating, but shows will also be streamed live to alternate venues.
This event is sponsored by the James Franck Institute, the Department of Physics, the Office of the Executive Vice President for Research, Innovation and National Laboratories, and the Materials Research Science & Engineering Center. The organizer of the Open House is Cheng Chin.
Professor Lutz H. Gade, Universität Heidelberg
Enantioselective Catalysis with 3D Transition Metal Complexes: Chiral Pincers as Stereodirecting LigandsKey challenges in the development of catalysts based on first row ("3d") transition metals include the substitutional lability of the open shell species involved, the changes of spin states in the individual reaction steps as well as the potential competition of single electron transfer steps. Most reaction sequences involve almost exclusively paramagnetic catalysts and catalytic intermediates. These properties render mechanistic studies challenging and also require care in the design of stereodirecting ligands.
Recently, we developed a new class of chiral pincer (“boxmi”) ligands which have been used in a variety of enantioselective transformations including alkylations of β-ketoesters and their subsequent cyclization to spirolactones, as well as the trifluoromethylation and azidation of β-ketoesters as well as oxindoles. Their iron(II) and manganese(II) complexes match the activity and selectivity of the most efficient noble metal catalysts for the hydrosilylation or hydroboration of ketones (Figure 1).
Figure 1. Highly active and enantioselective iron hydrosilylation catalyst for ketones.
The focus of the lecture will be the elucidation of the catalytic reaction mechanisms and the identification and characterization of the (frequently) paramagnetic species involved.
We acknowledge Funding by the Deutsche Forschungsgemeinschaft (DFG SFB 623 &
Ga 488/9-1&2), the Fonds der Chem. Industrie and the Alexander von Humboldt-Stiftung.
 Q.-H. Deng, H. Wadepohl, Lutz H. Gade, Chem. Eur. J. 2011, 17, 14922; Q.-H. Deng, R. L. Melen, L. H. Gade, Acc. Chem. Res. 2014, 47, 3162.
 Q.-H. Deng, H. Wadepohl, L. H. Gade, J. Am. Chem. Soc. 2012, 134, 2946; Q.-H. Deng, H. Wadepohl, L. H. Gade, J. Am. Chem. Soc. 2012, 134, 10769; Q.-H. Deng, T. Bleith, H. Wadepohl, L. H. Gade, J. Am. Chem. Soc. 2013, 135, 5356; T. Bleith, Q.-H. Deng, H. Wadepohl, L. H. Gade, Angew. Chem. Int. Ed. 2016, 55, 7852.
 T. Bleith, H. Wadepohl, L. H. Gade, J. Am. Chem. Soc. 2015, 137, 2456; T. Bleith, L. H. Gade, J. Am. Chem. Soc. 2016, 138, 4972; V. Vasilenko, C. K. Blasius, H. Wadepohl, L. H. Gade, Angew. Chem. Int. Ed. 2017, 56, 8393.
Julia Widom, University of Michigan
Structure and Dynamics of Nucleic Acids by Nonlinear Spectroscopy and Single-Molecule MicroscopyNucleic acids play central roles in many aspects of biology, acting as genetic material, catalysts, regulatory signals and more, and advances in optical spectroscopy and microscopy have provided significant insight into these biological functions. I will first present my work utilizing two-dimensional fluorescence spectroscopy (2DFS) to investigate the local conformations of nucleic acids. I initially used 2DFS to determine the solution conformation of a dinucleotide of the fluorescent nucleic acid base analogue 2-aminopurine, and it is now being extended to more complex DNA systems. I will then present ongoing work in which I am using single-molecule fluorescence microscopy to study the conformational dynamics of RNA in transcription and splicing complexes. I will focus on my work on riboswitches, which are RNAs that regulate bacterial gene expression in response to environmental cues. In the cell, RNA folds during its transcription by RNA polymerase (RNAP), and certain riboswitches function primarily by regulating the outcome of transcription. I investigated the interplay between riboswitch folding and transcription, finding that interactions between a riboswitch and RNAP concurrently aid in folding of the nascent riboswitch and stabilization of a paused state of RNAP. The discovery of this cross-coupling highlights the necessity of performing detailed biophysical studies of RNAs in their native biological contexts, which is a central goal of the research I plan to pursue as an independent investigator.
IME Distinguished Colloquium Series: Jay Gambetta, IBM
Ilya Nemenman, Emory University
Playing Newton: Learning equations of motion from dataArguably, science' goal of understanding nature can be formulated as inferring mathematical laws that govern natural systems from experimental data. With the fast growth of power of modern computers and of artificial intelligence algorithms, there has been a recent surge in attempts to automate this goal and to design, to some extent, an “artificial scientist.” I will discuss this emerging field, but will focus primarily on our own approach to it. I will introduce an algorithm that we have recently developed, which allows one to infer the underlying dynamical equations behind a noisy time series, even if the dynamics are nonlinear, and only a few of the relevant variables are measured. I will illustrate the method on applications to toy problems, including inferring the iconic Newton’s law of universal gravitation, as well as a few biochemical reaction networks. I will end with applications to experimental biological data: modeling the landscape of possible ! behaviora l states underlying reflexive escape from pain in a roundworm and (if time permits) modeling insulin secretion in pancreatic beta cells.
Dr. Amanda Cook, ETH Zürich
Mechanistic Studies of Catalytic Reactions in Solution and on Surfaces: C-H Functionalization and Hydroamination ReactionsUnderstanding the mechanisms of reactions is fundamental to both homogeneous and heterogeneous catalysis. The acetoxylation of arenes, borylation of methane, and hydroamination of alkynes reactions were studied, resulting in insights into catalyst reactivity and selectivity. In the acetoxylation of arenes, [(Pyridine)Pd(OAc)2]2 was found to be a highly active catalyst, and the mechanism of the reaction was determined. For methane borylation, the challenge of product selectivity was studied, and it was found that the catalyst [(Cp*)RuCl2]2 was not only the most selective, but indeed prefers methane as the substrate. The final reaction studied, the hydroamination of alkynes, was shown to be catalyzed by silica-supported Zn(II) ions, which was synthesized using a Surface Organometallic Chemistry approach. Through developing these catalysts, physical organic chemistry methods were used to understand their reactivity and selectivity, furthering our knowledge of both homogeneous and heterogeneous catalysis.
Chong Liu, Materials Science and Engineering, Stanford University
Materials Design and Electrochemical Methods for Water-Energy Nexus: From Water Purification to Resource MiningWater, resource, and energy are the foundation for the sustainable future. Applications in water-energy nexus require the control of phenomena that span enormous length scales. Materials design with precise atomic compositions and tailored microstructures as well as kinetics manipulation are the keys to achieve high performance. In this talk, I will first introduce the alternating current electrochemical method for resource mining from water. This method combined with surface functionalized electrodes can extract targeted resource species with extremely high capacity and selectivity. This method is successfully demonstrated for uranium extraction from seawater and heavy metals recovery from wastewater. It opens an eco-friendly route of mining from earth water system with minimal impact on the environment. Moreover, freshwater security is another focus of sustainability that is of paramount importance to public health, especially for developing areas with limited energy supply and insufficient infrastructures. By synthesizing nanomaterials with optimized physical properties and morphologies, we achieved rapid and efficient bacteria and viruses inactivation through photocatalysis and also enabled a new method based on electroporation.
Eugene Demler, Harvard
Stressed soft matter: softening, hardening and yielding soft solids.Time-dependent and process-dependent properties of soft jammed solids like gelled networks, compressed emulsions or colloidal glasses, stem from stress heterogeneities frozen-in during solidification and their coupling with an imposed deformation. I’ll discuss recent novel insights gained through numerical simulations of statistical microscopic models that suggest how to control the persistence of flow inhomogeneities upon yielding, and provide new cues to design softening, hardening and brittleness in soft solids.
Scott J. Miller, Yale University
Searching for Selective Catalytic Reactions in Complex Molecular EnvironmentsThis lecture will describe recent developments in our efforts to develop low-molecular weight catalysts for asymmetric reactions. Over time, our view of asymmetry has ebbed and flowed, with foci on enantioselectivity, site-selectivity and chemoselectivity. In most of our current work, we are studying issues of enantioselectivity as a prelude to extrapolation of catalysis concepts to more complex stereochemical settings where multiple issues are presented in a singular substrate. Moreover, we continuously examine an interplay between screening of catalyst libraries and more hypothesis-driven experiments that emerge from screening results. Some of the mechanistic paradigms, and their associated ambiguities, will figure strongly in the lecture.
Odd viscosity in chiral active fluidsEat chiral active food: 12:00
Hear about chiral active fluids: 12:15
Bettina Hoerlin and Gino Segrè
Enrico Fermi: The Pope of PhysicsEnrico Fermi has been called the last scientist who knew all of physics, having attained the heights of the profession as a theorist and experimentalist. Unique in numerous ways, this 20th century physicist was entirely self-taught; the breadth and depth of his research remain unparalleled. Fermi’s 1938 Nobel Prize was picked up en route in his flight from fascist Italy with his Jewish wife and children to a new life in America. In 1942 he became the lead scientist in the University of Chicago experiment that produced the first self-sustaining nuclear chain reaction, a key precursor to building the atomic bomb. His role in the success of the Manhattan Project was critical.
This lecture combines Fermi’s personal life with his scientific contributions and illustrates how he was shaped by history and how he, in turn, shaped history. Legendarily apolitical, Fermi was reluctantly involved in American political decision making during the war and afterwards. The many challenges he faced, including the tensions between politics and science, are still relevant today.
Lydia Kisley, University of Illinois at Urbana - Champaign
Proteins in Nanoporous Hydrogels: Adsorption, Diffusion, and FoldingProteins within nanoporous hydrogels have important biotechnological applications in pharmaceutical purification, tissue engineering, water treatment, biosensors, and medical implants. Yet, oftentimes proteins that are functional in solution lose activity when in contact with soft nanostructured materials due to perturbations in the folded state, conformation, diffusion, and adsorption dynamics of the protein by the material. We have developed several unique nanoscale fluorescent spectroscopies to image the heterogeneity of protein dynamics within hydrogels. First, we resolve adsorption kinetics of proteins to charged ligands within hydrogels used in pharmaceutical separations using location-based super resolution imaging to demonstrate the importance of the spatial charge distribution of the ligands. Next, we show the heterogeneity of the nanoscale pore size of the hydrogels can influence the diffusion of analytes within the pores using an in situ correlation-based super resolution imaging technique. Finally, we use fluorescence resonance energy transfer imaging combined with temperature jump perturbations to show that noncovalent interactions of the protein with the polymer surface are more important than confinement for determining the folding and stability of the protein within hydrogels. Overall, in situ observations of proteins in hydrogels using fluorescent spectroscopies can inform and inspire soft nanomaterial design to improve the performance, shelf life, and cost of the next generation of biomaterials.
Vern Schramm, Albert Einstein College of Medicine
Transition State Analogues as Drug CandidatesOur focus is on understanding enzymatic transition states. The approach is to use intrinsic kinetic isotope effects combined with computational chemistry to determine electrostatic potential maps of enzymatic transition states. Knowledge of these transition states provides chemical insights and permits the design of stable molecules as transition state mimics. Synthetic chemistry collaborators in New Zealand produce the transition state mimics. The design of transition state mimics has led to the most powerful inhibitors for over a dozen enzymes. One focus for enzyme inhibitor design is the family of N-ribosyltransferases. Three transition state analogues designed for the N-ribosyltransferases have entered clinical trials and others are in earlier stages of development. One of these was recently approved for use in relapsed or resistant peripheral T cell lymphoma in Japan. Comparison of target-drug interaction in vitro and in vivo provides insights for the action of tight-binding drug candidates. Research focus on transition states includes investigation of the fast protein motions that contribute to transition state formation. We use isotopically heavy enzymes and computational chemistry to establish the connection between fast dynamic protein motion and bond breaking at the transition state.
Emanuela Del Gado, Georgetown University
Stressed soft matter: softening, hardening and yielding soft solids.Time-dependent and process-dependent properties of soft jammed solids like gelled networks, compressed emulsions or colloidal glasses, stem from stress heterogeneities frozen-in during solidification and their coupling with an imposed deformation. I’ll discuss recent novel insights gained through numerical simulations of statistical microscopic models that suggest how to control the persistence of flow inhomogeneities upon yielding, and provide new cues to design softening, hardening and brittleness in soft solids.
The Tuesday JFI Seminar - Prof. John Parkhill, Department of Chemistry & Biochemistry, Notre Dame
Quantum dynamics with Statistical Effects and Statistical Models of Quantum EffectsThe capability of electronic structure to calculate the wavefunctions, and even dynamics of large systems has improved dramatically. This has put electronic structure into an uncomfortable regime where statistical effects become as important as the correlation problem. I will discuss our efforts to describe mixed-state electronic dynamics with density matrix equations of motion, and the applications of those theories to ultrafast experiments. Realtime mean field theories such as RT-TDDFT and RT-TDHF dominate applications because of the speed required to access picosecond timescales. Yet TDHF and TDDFT are not accurate enough to properly model resonant driving, which is only one ingredient in ultrafast spectroscopy. In this talk I discuss a simple density-matrix equation of motion implemented as an approximation to RT-TDDFT, which excites properly on resonance. Based on this foundation I compare the non-equilibrium steady states of the correct DFT and a Markovian bath model, with essentially exact results coming from HEOM showing that TDDFT can be used to study driven ultrafast dynamics. I then discuss self-consistency in correlated corrections to TDDFT which have low cost and can be applied to large systems. Statistical sampling of molecular geometries has become an equally important issue, although empirical density functionals, which are the most practical tools for exploring geometries, make an ambiguous mixture of quantum physics and statistical modeling. I will demonstrate purely statistical models of molecular structure, and show that in the near future it is likely that purely empirical models of the PES will have several appealing advantages over empirical hybrids. of quantum mechanical models with statistics.For further information please contact Brenda Thomas at 773-702-7156 or by email at firstname.lastname@example.org. You may also contact the Host, David Mazziotti at 773-834-1762 or via email at email@example.com.
Mark Spencer Rudner, Niels Bohr Instituet
Quantized magnetization density and the topology of anomalous Floquet insulatorsPeriodic driving can be used to induce a wide array of interesting phenomena in quantum many-body systems. In addition to providing means to induce artificial gauge fields or to realize familiar effective Hamiltonians, periodic driving opens a wide new world of intrinsically non-equilibrium quantum phases. Intriguingly, the topological classification of periodically-driven systems is more rich than that in equilibrium, allowing for a variety of "anomalous Floquet insulator" phases which feature characteristic patterns of nontrivial micromotion within each driving period. In this talk I will give an introduction to the unique features of topology in periodically-driven systems, and discuss the new quantized observables that can be used to detect them. In particular, I will focus on a two-dimensional system that features chiral edge states even though all bulk bands have vanishing Chern numbers and may be fully localized by disorder. This phase features a quantized orbital magnetization density in any filled region, which serves as a bulk topological order parameter for the phase (and applies in both interacting and non-interacting systems). I will discuss a proposal for how to measure the magnetization in a system of cold atoms in an optical lattice. Due to its chiral edge states, which are not localized by disorder, this phase provides an interesting platform for studying the interplay between thermalization and many-body localization.
Sigrid Nachtergaele PhD, University of Chicago
Uncovering the cellular functions of mRNA methylationSandwiches at 11:45; remember to bring a cup for coffee/tea.
AJ Boydston Associate Professor, Department of Chemistry University of Washington
Integrated Synthesis, Design, Additive Manufacturing, and Mechanoresponsive MaterialsFor this seminar, I hope to discuss two research thrusts from my program: Additive Manufacturing with Mechanoresponsive Materials, and Metal-Free Ring-Opening Metathesis Polymerization. Our research team focuses on the chemistry of additive manufacturing with emphasis on: 1) incorporation of functional materials, particularly those that respond via conversion of mechanical force into chemical reactivity; 2) expansion of the materials space available for AM; and 3) selective multi-material printing from “all-in-one” mixed-resin vats. As representative examples, we will discuss melt-material extrusion of custom mechanochromic filaments, novel formulations that enable inexpensive and efficient access to elastomeric components via vat photopolymerization, and progress toward parallel photo-radical/photo-cationic printing mechanisms for production of graded materials. Our longer-term research objectives center on the ability to integrate mechanoresponsive materials (molecular- to nanoscale), property gradation or heterogeneity (nano- to microscale), and object geometry (micro- to mesoscale) to answer key scientific questions about the interplay between mechanics (and dynamics) of lattice structures and chemo-mechanical coupling. A major synthetic effort of my program centers on the development of photoredox-mediated, metal-free methods for polymer synthesis. Recently, we discovered that visible light photoredox catalysis is a viable approach for conducting ring-opening metathesis polymerization (ROMP) of strained cycloalkenes. This divergence from metal-mediated polymerizations introduces a new mechanistic theme for ROMP with unique synthetic outcomes. We will present our fundamental studies on the mechanism of this polymerization and updates on our applications-oriented research toward commercialization.
Michael Pretko, UC Boulder
Higher Rank Quantum Spin Liquids: From Fractons to Mach’s PrincipleQuantum spin liquids are phases of matter exhibiting a variety of interesting properties, such as fractionalization and long-range quantum entanglement. These exotic phases possess a natural description in the language of gauge theory. While most spin liquids studied to date have been described by familiar vector gauge fields, there exists a broader class of stable spin liquid phases described by higher rank tensor gauge fields. In this talk, I will discuss the physics of three-dimensional spin liquids described by symmetric tensor gauge theories. Such theories are notable for their “subdimensional” gauge charges, which are forced to exist in lower-dimensional subspaces instead of propagating freely in three-dimensional space. In some cases, the charges will be fully immobile, in a manifestation of the “fracton” phenomenon. I will review the basic physics of subdimensional particles and their coupling to tensor gauge fields. As an illustrative example, I will discuss rank 2 spin liquids which exhibit the basic properties of emergent gravity. In particular, I will discuss how the fracton phenomenon can be understood as a direct consequence of Mach’s principle.
Sang Ouk Kim KAIST Chair Professor, Department of Materials Science & Engineering, KAIST
Liquid Crystalline Graphene Oxide Nanoscale Assembly for Functional StructuresGraphene Oxide Liquid Crystal (GOLC) is a newly emerging graphene based material, which exhibits nematic type colloidal liquid crystallinity with orientational ordering of graphene oxide flakes in good solvents, including water. Since our first discovery of GOLC in aqueous dispersion, this interesting mesophase has been utilized for many different application fields, such as liquid crystalline graphene fiber spinning, graphene membrane/film production, prototype liquid crystal display and so on. Interestingly, GOLC also allow us a valuable opportunity for the highly ordered molecular scale assembly of functional nanoscale structures. This presentation will introduce our current status of GOLC research particularly focusing on the nanoscale assembly of functional nanostructures. Besides, relevant research works associated to the nanoscale assembly and chemical modification of various nanoscale materials will be presented.
Andreas Trautner, University of Bonn
CP violation caused by another symmetryUnderstanding the origin of CP violation offers a new starting point to address the Standard Model flavor and strong CP puzzles.
Group theoretically, the physical CP transformation of the SM is a special outer automorphism ("symmetry of symmetry") of the theory
and I will explain what that means in detail.
Equipped with this, we can understand that beyond the Standard Model, there can be other outer automorphisms beyond the usual C,P or T transformations.
On the other hand, certain classes of symmetries do preclude the existence of CP transformations altogether in which
case CP is violated by calculable ("geometrical") phases. I will explain this based on two explicit example models:
In a special three Higgs doublet model the presence of outer automorphisms beyond CP allows for a super simple calculation of VEVs, a reduction of
the size of the parameter space by a factor of 24, anticipating the boundaries of the RGE flow and most interestingly,
the prediction of quantized CP violating phases. A second explicit example is a "Scalar-QCD" type of model in which the SU(3) gauge group is spontaneously broken to the small discrete subgroup T7.
In this case CP violation originates with quantized phases while the theta angle is protected at 0.
Abigail Knight, PhD, Arnold O. Beckman Postdoctoral Fellow, UCSB
Bioinspired Metal-Coordinating MaterialsCoordination of metal ions is critical to the structure and function of a variety of natural materials and allows a diverse array of capabilities currently unavailable to synthetic structures. This talk will highlight efforts towards mimicking two capabilities of natural materials: (1) the selective coordination of metal ions and (2) implementing metal ions to induce a morphological shift in self-assembled materials. Selective coordination is critical to the function of a variety of natural proteins, yet synthetic ligands with this capability are rare despite applications in heavy metal remediation, therapeutics, and recycling. A combinatorial platform implementing N-substituted glycine oligomers, or peptoids, was designed to identify motifs capable of chelating low concentrations of various metal ions in complex sample media. Amphiphilic marine siderophores have a more unique capability to undergo a morphological shift upon metal coordination. Inspired by these structures, coordinating peptide polymer amphiphiles were designed that undergo self-assembly directed by coordination geometry, adding to the toolbox of stimuli responsive materials.
Professor Jay Groves, University of California, Berkeley
Signal Transduction on Membrane SurfacesMost intracellular signal transduction reactions take place on the membrane surface. The membrane provides much more than just a surface environment on which signaling molecules are concentrated. There is a growing realization that multiple physical and chemical mechanisms allow the membrane to actively participate in the signaling reactions. Using a combination of single molecule imaging and spectroscopic techniques, my research seeks to directly resolve the actual mechanics of signaling reactions on membrane surfaces both in reconstituted systems and in living cells. These observations are revealing new insights into cellular signaling processes as well as some unexpected functional behaviors of proteins on the membrane surface.
Gil Rafael, Caltech
Topological frequency conversion in strongly driven quantum systemsWhen a small quantum system is subject to multiple periodic drives, it may realize multidimensional topological phases. In my talk, I will explain how to make such constructions, and show how a spin-1/2 particle driven by two elliptically-polarized light beams could realize the Bernevig-Hughes-Zhang model of 2 topological insulators. The observable consequence of such construction is quantized pumping of energy between the two drive sources.
Yuval Elhanati, Princeton University
Probabilistic Inference of the Adaptive Immune SystemThe adaptive immune system can recognize many different threats by maintaining a large diversity of cells with different membrane receptors. We study the complex stochastic processes that generate and shape this ensemble of immune receptors using probabilistic models. These models can be inferred from high throughput sequence data using statistical algorithms. Specifically, we can use a technique based on transfer matrices formulation to learn the probabilistic properties of the generation process. We can then model also selection effects on the generated cells using maximum likelihood methods. Our methods allow us to characterize and study the diversity of the distribution beyond the sample data itself, disentangling and uncovering the details of the biological processes shaping it. We find universality - different individuals, humans and mice separately, have very similar underlying processes shaping the repertoire. This universality in turn acts as a baseline for further study of the system under perturbations such as infections or vaccination. Eventually we plan to harvest the statistical power of the models to diagnose and help plan treatments to clinical conditions from infections to cancer.
Professor Preston Snee, University of Illinois at Chicago
Transient X-Ray Absorption of Semiconductor Quantum Dots Reveals New Charge Transport Phenomenon
Elizabeth R Chen, mathe·magician
« having a ball » part II: spherical parking¿¿ what is more FUN than
playing with beach ball & projector markers ??
¡¡ doing actual math with them, of course !!
this continues the Atrium talk from Thursday
JOIN US for hands·on exploration of spherical parking
bring your lunch
Eric Isaacs, University of Chicago
CP-1: The 'Big Bang' of Big ScienceChicago Pile-1 marked a milestone in science -- and, indeed, in human history. But beyond the scientific impact of that first human-made self-sustaining nuclear chain reaction, CP-1 forever changed the way scientists and institutions work together, creating a new interdisciplinary model that reshaped the University's approach to scientific research and led directly to the founding of the National Laboratories and today's big science initiatives.
Evan Miller, University of California, Berkeley
Electrophysiology: Unplugged. New Chemical Tools to Watch Cell PhysiologyThis presentation will describe progress towards the use of voltage-sensitive fluorescent dyes to measure changes in cellular and neuronal membrane potential. The Miller lab is developing new methods for voltage imaging that rely on photoinduced electron transfer (PeT) as a voltage-sensing trigger to achieve fast, sensitive, and non-disruptive optical measurements of membrane potential. I will discuss recent progress on new, long-wavelength voltage indicators for use in neuronal systems, progress towards genetically targeting these indicators to defined cells, and new methods to explore the physiology non-excitable cells.
Hod Lipson, Columbia University
Uncovering lurking order in time-series dataFrom automatic speech recognition to discovering unusual stars, underlying almost all automated discovery tasks is the ability to compare and contrast data streams with each other, to identify connections and spot outliers. Despite the prevalence of data, however, automated methods are not keeping pace. A key bottleneck is that most data comparison algorithms today either rely on a human expert to specify what ‘features’ of the data are relevant for comparison, or require copious amounts of data for machine learning. Data Smashing is a new principle for estimating the similarity between the sources of arbitrary data streams, using neither domain knowledge nor learning. We demonstrate the application of this principle to the analysis of data from a number of real-world challenging problems, including the disambiguation of electro-encephalograph patterns pertaining to epileptic seizures, detection of anomalous cardiac activity from heart sound recordings and classification of astronomical objects from raw photometry. In all these cases and without access to any domain knowledge, performance is on a par with the accuracy achieved by specialized algorithms and heuristics devised by domain experts. Work done with Ishanu Chattopadhyay.
The Tuesday JFI Seminar - Erez Berg, Department of Physics, University of Chicago
Bad Metals and Bad Insulators: A View from the Large-N limitIn normal metals, the electron's mean free path is much larger than its wavelength, allowing a semiclassical treatment of transport. Conversely, whenever scattering is so strong that the mean free path becomes comparable to the electron's wavelength, the concept of a quasiparticle becomes ill defined, and a new theoretical framework is needed. I will introduce a family of lattice models for interacting electrons that can be solved exactly in the limit of a large number of interacting electron flavors and/or phonon modes. Depending on details, these models exhibit either "resistivity saturation" at high temperatures to a value of the order of the quantum of resistance, or "bad metallic behavior" where the resistivity grows without bound with increasing temperature. Translationally invariant higher-dimensional generalizations of the Sachdev-Ye-Kitaev model can capture a variety of phenomena arising purely from electron-electron interactions, including local criticality, non-Fermi liquid, and marginal Fermi liquid behavior. I will describe the implications of these results for the problem of non-quasiparticle transport at large, local quantum criticality, and the relation between transport and the development of quantum chaos.
Timothy White Air Force Research Laboratory; Materials and Manufacturing Directorate
Pixelated Polymers: Directing the Self-Assembly of Liquid Crystalline ElastomersLiquid crystalline materials are pervasive in modern society. It has been long-known that liquid crystalline materials in polymeric forms also exhibit exceptional characteristics in high performance applications such as transparent armor or bulletproof vests. A specific class of liquid crystalline polymeric materials referred to as liquid crystalline elastomers were predicted by de Gennes to have exceptional promise as artificial muscles, owing to the unique assimilation of anisotropy and elasticity. Subsequent experimental studies have confirmed the salient features of these materials, with respect to other forms of stimuli-responsive soft matter, are actuation cycles of up to 400% as well “soft elasticity” (stretch at minimal stress). In this presentation, I will summarize our recent efforts in developing materials chemistry amenable to directed self-assembly. Enabled by these chemistries and processing methods, we have prepared liquid crystal elastomers with distinctive actuation and mechanical properties. Notably, these materials are homogenous in composition (lacking material/material interfaces). Relevance of this work to implementations in aerospace and commercial applications will be discussed.
James Shorter PhD, University of Pennsylvania
Reversing aberrant phase transitions of RNA-binding proteins connected to ALS and FTDRNA-binding proteins (RBPs) with prion-like domains (PrLDs) phase transition to functional liquids, which can mature into aberrant hydrogels composed of pathological fibrils that underpin fatal neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Several nuclear RBPs with PrLDs including TDP-43, FUS, hnRNPA1, and hnRNPA2 mislocalize to cytoplasmic inclusions in ALS and FTD and mutations in their PrLDs can accelerate fibrillization and cause disease. Here, I will discuss our latest endeavors to uncover and engineer therapeutic protein disaggregases to reverse these aberrant phase transitions and restore functional RBPs to the nucleus to counter ALS and FTD disease phenotypes.
Mercouri G. Kanatzidis, Northwestern University
3D and 2D Halide Perovskites: Poor Man's High Performance SemiconductorsThree-(3D) and two-dimensional (2D) layered halide perovskites are highly promising candidates for optoelectronic applications, and this has sparked new investigations of these materials from the synthetic, physicochemical and applications point of view. The 3D versions of these compounds adopt the three-dimensional ABX3 perovskite structure, which consists of a network of corner-sharing BX6 octahedra, where the B atom is a divalent metal cation (typically Ge2+, Sn2+ or Pb2+) and X is a monovalent anion (typically Cl−, Br−, I−); the A cation is selected to balance the total charge and it can be a Cs+ or a small molecular species. Such perovskites afford several important features including excellent optical properties that are tunable by controlling the chemical compositions, they exhibit ambipolar charge transport with high mobilities. Another class of materials gaining significance are the two-dimensional (2D) perovskites -a blend of perovskites with layered crystal structure- (Ruddlesden-Popper type) offer a greater synthetic versatility and allow for more specialized device implementation due to the directional nature of the crystal structure. A remarkable advantage of the 2D perovskites is that their functionality can be easily tuned by incorporating a wide array of organic cations into the 2D framework, in contrast to the 3D analogues which have limited scope for structural engineering. We also present the new homologous series, (C(NH2)3)(CH3NH3)nPbnI3n+1 (n = 1, 2, 3), of layered 2D perovskites which is different from Ruddlesden-Popper type. Structural characterization by single-crystal X-ray diffraction reveals that these compounds adopt an unprecedented structure type which is stabilized by the alternating ordering of the guanidinium and methylammonium cations in the interlayer space (ACI). The these 2D perovskites combine structural characteristics from both Dion-Jacobson (DJ) and Ruddlesden-Popper (RP) structure archetypes. Compared to the more common Ruddlesden-Popper (RP) 2D perovskites, the perovskites we describe here have a different stacking motif and adopt a higher crystal symmetry.
Jennifer Stockdill, Wayne State University
Strategies and Methods for the Synthesis of Neuroactive Disulfide-Linked Peptides
Chiral fluids, surface waves, and the inherent instability of odd viscosity fluidsWarm up: 12:00 bring lunch
OK GO: 12:15
IME Distinguished Colloquium Series: Uli Weisner, Cornell University
Molecular Engineering of Functional Hybrid NanomaterialsGlobal problems including energy conversion and storage, clean water and human health require increasingly complex, multi-component and functional materials with unprecedented control over composition, structure, and order down to the nanoscale. This talk will give examples for the rational design of novel functional hybrid nanomaterials inspired by biological examples. Discussion will include formation of self-assembled hybrid nanoparticles as well as polymer-nanoparticle self-assembly derived synthetic porous materials with amorphous, polycrystalline, and epitaxially grown single-crystal structures. Experiments will be compared to theoretical predictions to provide physical insights into formation principles. The aim of the described work is to understand the underlying fundamental chemical, thermodynamic and kinetic formation principles enabling generalization of results over a wide class of materials systems. Examples will cover the formation of hierarchical structures at equilibrium as well as via processes far away from equilibrium. Targeted applications of the prepared systems will include the development of ultrasmall fluorescent hybrid probes for nanomedicine (“C dots”), nanostructured hybrids for energy conversion and storage devices, self-assembled asymmetric ultrafiltration membranes, as well as the formation of first self-assembled superconductors.
MRSEC / KRUSS Surface Science Seminar
Surface Chemistry Measurements, Applications, and Instrumentation9:00 AM - 9:10 AM Welcome and Introduction
9:10 AM - 10:10 AM Contact Angle/Liquid-Solid Interface/Surface Free Energy, Dr. Raymond Sanedrin, KRUSS Scientific Instruments, Inc.
10:15 AM – 10:30 AM DSA Droplet Drying : Analysis of Water Adhesion to Flexible Mesh, Kelliann Koehler, Tian Group
10:35 AM – 11:35 AM Surface/ Interfacial Tension Liquid-Air Interface by Mark McCarthy, KRUSS Scientific Instruments, Inc.
11:40 AM – 11:55 AM Scaling puzzles of forced wetting, Mengfei He, Nagel Group
11:55 AM – 12:00 PM Questions? (ALL)
12:00 PM – 1:00 PM Lunch Break
1:05 PM – 1:35 PM Foam Analysis/Bubble Structure/Liquid Content, Mr. Art Kasson, KRUSS Scientific Instruments, Inc.
1:45 PM – 5:00 PM Demos K100, DSA100, MSA, SDT
Rodney Ewing, Stanford University
Projecting Risk into the Future: Failure of a Geologic Repository and the Sinking of the TitanicOver one hundred years ago, the “unsinkable” RMS Titanic struck an iceberg in the North Atlantic and sank on its maiden voyage from Southampton, UK, to New York City. This “accident” and others, such as the tragedy at Fukushima Daiichi, can provide insight into the challenges that face the geologic disposal of radioactive waste. In this presentation, I reflect on the essential differences between analyzing the failure of engineered structures vs. a “failed” geologic repository. Perhaps, the most important difference is that for most countries there will only be a single repository, and we will never “see” that repository “in operation,” as the operational phase of a geologic repository comes long after it has been filled with waste and sealed. The time-scales considered for the geologic disposal of radioactive waste place special demands on the analysis of how engineered and geologic systems might fail. As scientists and engineers, we should reflect on the sobering reality of how difficult it is to project the future behavior of a geologic repository over extended spatial and temporal scales that stretch over tens of kilometers and out to a hundreds of thousands of years. I will offer a few short observations on the state of the U.S. nuclear waste management program and ideas for moving forward.
Jiwoong Park, University of Chicago
3D Circuitry and Folding with 2D CrystalsTwo thousand years ago, the mass-manufacturing of paper simplified all aspects of information technology: generation, processing, communication, delivery and storage. Similarly powerful changes have been seen in the last century through the development of integrated circuits based on silicon. Monolayers of 2D crystals provide an ideal material platform for realizing these integrated circuits thin and free-standing, which were the key advantages of paper over other medium two thousand years ago. Once realized, these atomically thin circuits will be foldable and actuatable, which will further increase the device density and functionality, allowing them to be used tether-free (or wirelessly) in environments not previously accessible to conventional circuits, such as water, air or in space. In this talk, we will discuss our recent progresses toward building atomically-thin integrated circuits using wafer-scale 2D crystals. In order for this, we developed a series of a! pproaches that are scalable, precise, and modular. We developed wafer-scale synthesis of three atom thick semiconductors, reported a wafer-scale patterning method for one-atom-thick lateral heterojunctions, and showed how atomically thin films and devices can be vertically stacked to form more complicated 3D circuitry. Then we will discuss our most recent efforts to turn these 2D circuits into 3D structures.
The Tuesday JFI Seminar - Prof. Jiangping Hu, Institute of Physics, Chinese Academy of Science
Genes of Unconventional High Temperature SuperconductorsIn the past, both cuprates and iron-based high temperature superconductors (High Tc) were discovered accidentally. Lacking of successful predictions on new high Tc is one of major obstacles to reach a consensus on unconventional high Tc mechanism.
In this talk, we address the key question related to these two special materials: Why are Cu and Fe special? We answer this question by suggesting a common electronic gene behind these two families of materials. The common electronic gene explains their rareness as unconventional high Tc superconductors and can guide us to search for new high Tc materials. We extend this idea to predict possible unconventional high Tc superconductors. Verifying the prediction can convincingly establish high Tc superconducting mechanism and pave a way to design new high Tc superconductors. Host; Cheng Chin, 2-7192 or via email at firstname.lastname@example.org. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or by email at email@example.com.
Michael R. Wasielewski, Northwestern University
Singlet Fission in Organic Semiconductors: A Path to Enhanced Solar Cell Efficiencies
Yang Qin, University of New Mexico
Design, Preparation and Application of Organic/Inorganic Hybrid MaterialsIn this presentation, I will describe our research efforts in developing bottom-up approaches toward organic/inorganic hybrid materials with tailor-designed chemical structures, controlled nanomorphologies and specifically targeted functions. First, a versatile toolbox employing supramolecular chemistry that is capable of precisely nanostructuring multi-component hybrid materials through self-assembly processes is described. Specifically, we show that well-defined conjugated polymer (CP)/fullerene core-shell composite nanofibers (NFs) can be obtained through cooperation of orthogonal non-covalent interactions including block copolymer (BCP) self-assembly, CP crystallization, fullerene aggregation and hydrogen bonding interactions. Organic photovoltaic (OPV) devices applying these NFs display improved controllability of morphologies at both macroscopic and microscopic levels, as well as enhanced efficiencies and stability, over their conventional bulk heterojunction (BHJ) counterparts. Secondly, I discuss the design and synthesis of a new class of Pt-containing small molecules possessing unusual "roller-wheel" shaped geometry, leading to improved crystallinity and inter-molecular interaction, as well as higher OPV performance than previously reported Pt-containing CPs. Lastly, our recent efforts in controlling nanomorphologies of metal-organic frameworks (MOFs) will be discussed. By using a templated growth mechanism, well-defined one-dimensional MOF nanotubes and nanorods could be obtained by simply varying the reactant concentrations. Interestingly, single crystalline MOF nanowires could be obtained by using a template with smaller pore dimensions, revealing useful information on the MOF growth mechanisms under spatially confined environment.
Coordinated Dance of levitating particles in a thermal cellad-hoc discussion: 12:00
the dance begins: 12:15
Chin-Tu Chen, University of Chicago
"Atoms for Peace" in Medicine and BiologyCP-1’s impact on biomedicine has been far-reaching and long-lasting, including the direct benefits of enabling fundamental biomedical research and also of saving numerous human lives. Man-made radioisotopes, produced either by nuclear reactors or particle accelerators, have been widely used for both diagnosis and treatment of major health abnormalities such as cancers, cardiovascular diseases, brain and behavior disorders, diabetes, tissue and organ injuries, etc. Radiation related technologies, many originated from nuclear physics, high-energy physics, etc., have also helped advance the development of multiple generations of biomedical imaging and therapy instruments with increasingly more and better functionalities over the last eight decades. These radiation related R&D have led to earlier and more accurate diagnosis of diseases and more efficient and effective treatments of patients, resulting in substantial saving in both human lives and societal resources.
One of the spin-offs from the CP-1 is the establishment of the Argonne Cancer Research Hospital (ACRH) at The University of Chicago in 1953 - renamed later as the Franklin McLean Memorial Research Institute (FMI) in 1970s - for research on the peaceful use of atomic and nuclear energy in medicine and biology. Early researchers at the ACRH/FMI had pioneered the development of new imaging and therapeutic radiotracers including the first clinical use of Tc-99m to detect brain tumor and more effective production of I-125 for both research and clinical uses, designing and developing novel approaches in radiation therapy and chemotherapy for treating cancer, identification of chromosomal translocation as the cause of leukemia and other cancers, discovery of erythropoietin (EPO) and development of its purification methods, etc. These and other UChicago research contributions are representative of a much broader scope of the impact of PC-1 on medicine and biology in general, which has been actively continuing and expanding into the future.
Paramjit S. Arora, New York University
Protein Domain Mimics as Modulators of Protein-Protein InteractionsProtein−protein interactions (PPIs) are ubiquitous in biological systems and often misregulated in disease. As such, specific PPI modulators are desirable to unravel complex PPI pathways and expand the number of druggable targets available for therapeutic intervention. However, the large size and relative flatness of PPI interfaces make them challenging molecular targets. This presentation will describe our systematic approach using secondary and tertiary protein domain mimics (PDMs) to specifically modulate PPIs. Our strategy focuses on mimicry of regular secondary and tertiary structure elements from one of the PPI partners to inspire rational PDM design. Current applications of the overall approach to develop small molecule cancer therapeutics will be discussed.
The Tuesday JFI Seminar - Dr. Kin Chung Fong, Raytheon BBN Technologies
Looking for Relativistic Hydrodynamics in Solid State PhysicsInteractions between the Dirac fermions in graphene can lead to
new collective behavior described by hydrodynamics. By listening
to the Johnson noise of the electrons, we are able to probe
simultaneously the thermal and electrical transport of the Dirac fluid
and observe how it departs from Fermi liquid physics. At high
temperature near the neutrality point, we find a strong
enhancement of the thermal conductivity and breakdown of
Wiedemann-Franz law in graphene. This is attributed to the non-
degenerate electrons and holes forming a strongly coupled Dirac
fluid. We shall take an outlook on the hydrodynamic physics
experiments in solid state systems. Ref: Science 351, 1058 (2016)
For further information contact: Host: Dam Thanh Son, 773-834-9032. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or via email to firstname.lastname@example.org.
Xiao Wang, Stanford University
RNA-Centered Perspective of Gene Expression in Time and Space
Professor Noah Burns, Stanford University
Synthesis and Study of Unusual Lipids
Making Majoranas in Silicon: twisting electrons for quantum information on the cheapfeed body: 12:00
feed mind: 12:15
Robert (Bo) Jacobs, Hiroshima Peace Institute and Hiroshima City University
The Fallout of Chicago Pile-1
The critically important Chicago Pile-1 experiment midwifed both nuclear energy and nuclear weaponry into our world. Few single experiments have shaped human society with the depth of the first controlled nuclear chain reaction. This talk outlines the social impacts of both nuclear weapons and nuclear power during the last 75 years. Beyond this survey, it examines the discourse of human competence that belies both nuclear technologies and facilitates beliefs that we can control apocalyptic weaponry, and safely manage high-level nuclear waste for thousands of generations.
Tom Witten, University of Chicago
How asymmetric colloidal particles create hyperuniform dispersionsHyperuniformity of a many-body system means anomalously small density fluctuations. In an ordinary liquid or solution the mean-squared fluctuations E(N - E(N))^2 of particle number N in a given region are proportional to the average particle number E(N). By contrast, in a hyperuniform system E(N - E(N))^2/E(N) goes to 0 as N goes to infinity. The classic example is the one-component plasma, a gas of charged particles with a uniform neutralizing background charge. Recently granular materials and periodically sheared colloidal dispersions were shown to be hyperuniform. We investigate the question of uniformity in a dilute colloidal dispersion in which particles are settling under gravity. When the particles are of generic shapes, their asymmetry strongly affects their interaction via the coupling between orientation, drag and fluid velocity gradients. Two isolated objects generally separate over time. In one regime hyperuniform and anisotropic behav! ior of th e density correlation function probed by light scattering is inevitable.
 S.Torquato, Rev. Mod. Phys, vol.82, 2633-2640 (2010).
 D. Hexner and D. Levine, Phys. Rev. Lett., vol.114, 110602 (2015).
The Tuesday JFI Seminar - Prof. Sabre Kais, Department of Chemistry, Purdue University
Near Term Applications of Quantum Simulation and Quantum Computing DevicesThe exact solution of the Schrödinger equation for atoms, molecules and extended systems continues to be a “Holy Grail” problem for the field of atomic and molecular physics since inception. Recently, breakthroughs have been made in the development of hardware-efficient quantum optimizers and coherent Ising machines capable of simulating hundreds of interacting spins through an Ising-type Hamiltonian. One of the most vital questions associated with these new devices is: “Can these machines be used to perform electronic structure calculations?” In this talk I will discuss the possibility of mapping the electronic structure Hamiltonian to an Ising type Hamiltonian and present the simulation results of the transformed Ising Hamiltonian for small molecules such as H2, He2, HeH+, LiH and H2O. Future directions for scaling up the simulations to larger systems will be also discussed.For further information please contact Brenda Thomas at 773-702-7156 or by email at email@example.com. You may also contact the Host, David Mazziotti at 773-834-1762 or via email at firstname.lastname@example.org.
IME Distinguished Speakers in Technology & Industry: Darlene Solomon, Agilent Technologies
A View into the "Century of Biology" and AgilentTechnology leadership based on a culture of innovation, contribution and sustained R&D investment has been at the core of Agilent's success through decades of market and technology waves. Today, biology is the field where science and understanding are most rapidly changing. This talk will highlight key megatrends in this 'century of biology', Agilent's transition from being a predominantly electronics and semiconductor company into one fully-focused on the life science and diagnostics industries, and some of the technology contributions underway at Agilent that will underlie tomorrow's breakthroughs.
Professor Sukbok Chang, KAIST
Development of Direct C-H Amination Reactions
George S. Sheppard, ABBVIE
The discovery of BET Bromodomain Inhibitor ABBV-075
Shubhayu Chatterjee, Harvard University
Intertwining topological order and discrete broken symmetries in the hole-doped cuprates via quantum fluctuating antiferromagnetismThe enigmatic pseudogap metal phase of the hole-doped cuprate superconductors has two seemingly unrelated characteristics: (i) a gap in the electronic spectrum along the axes of the square lattice Brillouin zone, and (ii) the presence of discrete broken symmetries (like rotation, inversion or time-reversal). In a normal metal with full translational symmetry, a gap in the electron spectrum in the anti-nodal region cannot be explained by such broken symmetries. We propose a resolution to this puzzle by intertwining topological order with broken symmetries in the pseudogap metal. We show that the required flavors of topological order, corresponding to precisely the broken symmetries observed in the cuprates, arise naturally in a SU(2) gauge theory of quantum fluctuations of magnetically ordered phases that lie proximate to the Néel phase. We explore how alternative descriptions of fluctuating Néel antiferromagnets, in terms of the semiclassical O(3) non-linear σ model, and the CP1 model, also naturally lead to the same phases. If time permits, we will also discuss comparisons between the gauge theory and recent numerical (DMFT and QMC) results on the two-dimensional Hubbard model.
Professor Xavier Roy, Columbia University
Molecular Clusters: Building Blocks for Nanoelectronics and Material Design
Two shades of forced wettingEat: high noon
Talk: high 12:15
Melissa Franklin, Harvard University
Dear Maria, Oh My, How Particle Physics has ChangedThis talk will in effect be a letter to Maria Goeppert-Mayer and other pioneering women particle physicists, describing both a brief history of the particle accelerators that have made remarkable discoveries in particle physics possible and the slow turn of experimentalists attention from the discovery of the building blocks of matter to the study of the universe with nothing in it, the so-called vacuum.
Juan De Pablo, University of Chicago, IME
Emerging Insights into Directed Assembly: Taking Examples from Nature to Design Synthetic ProcessesThere is considerable interest in controlling the assembly of polymeric material in order to create highly ordered materials for applications. Such materials are often trapped in metastable, non-equilibrium states, and the processes through which they assemble become an important aspect of the materials design strategy. An example is provided by di-block copolymer directed self-assembly, where a decade of work has shown that, through careful choice of process variables, it is possible to create ordered structures whose degree of perfection meets the constraints of commercial semiconductor manufacturing. As impactful as that work has been, it has focused on relatively simple materials – neutral polymers, consisting of two or at most three blocks. Furthermore, the samples that have been produced have been limited to relatively thin films, and the assembly has been carried out on ideal, two-dimensional substrates. The question that arises now is whether one can tra! nslate th ose achievements to polymeric materials having a richer sequence, to monomers that include charges, to three-dimensional substrates, or to active systems that are in a permanent non-equilibrium state. Building on discoveries from the biophysics literature, this presentation will review recent work from our group and others that explains how nature has evolved to (1) direct the assembly of nucleic acids into intricate, fully three-dimensional macroscopic functional materials that are not only active, but also responsive to external cues, and (2) to direct the assembly of polymeric actin and tubulin filaments into liquid crystalline phases, where the interplay between elasticity and activity can be used to manipulate the dynamics of the system. The results presented in this talk will then be used to discuss how one might design a new generation of synthetic active systems capable of performing specific, engineered functions.
Professor Christophe Coperet, ETH Zurich, Wheland Lecture
Surface Coordination Chemistry
The Tuesday JFI Seminar - Prof. Wassem Bakr, Department of Physics, Princeton University
Site-Resolved Microscopy of Ultracold Fermi-Hubbard Systems in new RegimesThe ability to probe and manipulate ultracold fermions in optical lattices at the atomic level using quantum gas microscopes has enabled quantitative studies of Fermi-Hubbard models in a temperature regime that is challenging for state-of-the-art numerical simulations. Experiments have focused on spin-balanced gases of repulsively interacting atoms with the hope of elucidating phenomena in high-temperature superconductors. In this talk, I will present experiments that explore the Hubbard model in two new regimes: repulsive gases with spin-imbalance and attractive spin-balanced gases. In the first regime, we observe canted antiferromagnetism at half-filling, with stronger correlations in the direction orthogonal to the magnetization. Away from half-filling, the polarization of the gas exhibits non-monotonic behavior with doping, resembling the behavior of the magnetic susceptibility of the cuprates. The attractive Hubbard model studied in the second set of experiments is the simplest theoretical model for studying pairing and superconductivity of fermions in a lattice. Our measurements on the normal state reveal checkerboard charge-density wave correlations close to half-filling. The charge-density-wave correlations are a sensitive thermometer in the low temperature regime relevant for future studies of inhomogeneous superfluid phases in spin-imbalanced attractive gases.For further information please contact Brenda Thomas at 773-702-7156 or by email at email@example.com. You may also contact the Host, Jonathan Simon at 773-702-9661 or via email to firstname.lastname@example.org.
Professor Christophe Coperet, ETH Zurich, Wheland Lecture
NMR Chemical Shifts: Beyond Numbers and How to Use them to Decode the Reactivity of Organometallic Compounds
Professor Christophe Coperet, ETH Zurich, Wheland Lecture
Molecular Understanding and Controlled Functionalization of Surfaces Towards Single-Site Catalysts and Beyond
blob of self-confining turbulence12:00 staging: bring lunch
12:15 execution: launch
Carlo Rubbia, Nobel Prize in Physics 1984
Nigel Goldenfeld, University of Illinois
The life and death of turbulenceHow do fluids become turbulent as their flow velocity is increased? During the last ten years, exquisite experiments, numerical simulations and pure theory have uncovered a remarkable series of connections between transitional turbulence, phase transitions and renormalization group theory, high energy hadron scattering, the statistics of extreme events, and even population biology. In this talk, I will outline how these developments and strange connections imply that a fluid at the boundary between turbulence and laminar flow behaves precisely like an ecosystem at the verge of extinction, a prediction that is supported by recent experiments.
The Tuesday JFI Seminar - Prof. Philip Kim, Department of Chemistry, Harvard University
Materials in 2-dimension and Beyond: Platform for Novel Electronics and OptoelectronicsHeterogeneous interfaces between two dissimilar materials are an essential building block for modern semiconductor devices. The 2-dimensional (2D) van der Waals (vdW) materials and their heterostructures provide a new opportunity to realize atomically sharp interfaces in the ultimate quantum limit for the electronic and optoelectronic processes. By assembling atomic layers of vdW materials, such as hexa boronitride, transition metal chalcogenide and graphene, we can construct atomically thin novel quantum structures. Unlike conventional semiconductor heterostructures, charge transport in of the devices is found to critically depend on the interlayer charge transport, electron-hole recombination process mediated by tunneling across the interface. We demonstrate the enhanced electronic optoelectronic performances in the vdW heterostructures, tuned by applying gate voltages, suggesting that these a few atom thick interfaces may provide a fundamental platform to realize novel physical phenomena. In this presentation, we will discuss several recent development of electronic and optoelectronic properties discovered in the van der Waals heterostructures, including hydrodynamic charge flows, cross-Andreev reflection across the quantum Hall edges states, and interlayer exciton formation and manipulations. For further information please contact Brenda Thomas at 773-702-7156 or by email at email@example.com. You may also contact the Host, Jiwoong Park at 773-834-3179 or via email at firstname.lastname@example.org.
Tracy M. Handel, PhD, Dept. of Pharmacology, School of Medicine, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego.
Structure, Activation & Inhibition of Chemokine Receptors
Professor Dale L. Boger, Stiegliitz Lecture
Redesign of Vancomycin for Resistant Bacteria
Dr. Cynthia J. Jenks, Argonne National Laboratory
A Quasi-Walk Along the Surfaces of Quasicrystals and Argonne InterfacesFor ages, scientists considered a crystal to be a solid with a repetitive internal structure. This notion was dismantled when quasiperiodic materials were discovered. Much has been learned about these fascinating intermetallic materials since their discovery and their subtleties are even more complex than imagined early on. In this talk, the growth, structure and stability characteristics of quasicrystalline materials will be discussed. Emphasis will be on their surfaces, known to have unusual characteristics, and of which scanning probe microscopies have produced some spectacular images and local probes of composition and structure, particularly low-energy ion scattering, show interesting findings. In addition, the talk will highlight ongoing research in the chemical sciences at Argonne National Laboratory and opportunities for collaborations.
Barbara Jacak, UC Berkeley and Lawrence Berkeley National Lab
Nuclear Physics: Then and Now
IME Distinguished Colloquium Series: Jens Norskov, Stanford University
A Molecular View of Heterogeneous CatalysisThis lecture will outline a theory of heterogeneous catalysis that allows a detailed understanding of elementary chemical processes at transition metal surfaces and singles out the most important parameters determining catalytic activity and selectivity. It will be shown how scaling relations allow the identification of descriptors of catalytic activity and how they can be used to construct activity and selectivity maps for both thermal and electro-catalytic processes. The maps can be used to define catalyst design rules and examples of their use will be given.
Manu Prakash, Stanford University
Life in flatland: Toy models and systems to explore origins of behavior in non-neuronal ensemblesDiverse multi-cellular animals encode a breathtaking diversity of natural behaviors. Non local interactions in traditional nervous systems make the study of underlying origins of behavior in animals difficult (and fascinating). It is a well known fact that simple dynamical systems can also encode perplexing complexity with purely local update rules. In this talk, using a variety of toy models and systems, we will explore how complex behavior can arise in non-neuronal ensembles; or in short "how do animals with no brains (neurons), decide, compute or think?
The Tuesday JFI Seminar - Dr. Sho Yaida, Department of Chemistry, Duke University
Novel Phase Transition within Amorphous SolidsGlassy materials are omnipresent in everyday life from windows to plastics to piles of sand. Yet our understanding of both their (equilibrium) liquid and (out-of-equilibrium) solid phases lags far behind that of crystalline counterparts. Recent advances are rapidly changing the ways in which we understand these common-yet-physically-enigmatic materials. This talk overviews one such advance -- the discovery of the Gardner phase transition from normal to marginally-stable glasses. Our work in particular indicates that such a transition, first found in abstract infinite-dimensional models, can survive down to the three-dimensional world. This transition reinforces the overriding role of rugged free-energy landscapes that dictate physics of glassy systems, with tangible consequences on jamming, yielding, and beyond.
For further information please contact Brenda Thomas at 773-702-7156 or by email at email@example.com. You may also contact the Host, Arvind Murugan at 773-834-3146 or via email at firstname.lastname@example.org.
Manu Prakash, PhD, Bioengineering, Stanford University
Life in flatland: Emergent origins of behavior in non-neuronal systemsDiverse multi-cellular animals encode a breathtaking diversity of natural behaviors. Non local interactions in traditional nervous systems make the study of underlying origins of behavior in animals difficult (and fascinating). It is a well-known fact that simple dynamical systems can also encode perplexing complexity with purely local update rules. In this talk, using a variety of toy models and systems, we will explore how complex behavior can arise in non-neuronal ensembles; or in short "how do animals with no brains (neurons), decide, compute or think?”.
Professor Bryan Dickinson, University of Chicago
Molecular Imaging and Evolutionary Approaches to Probe and Control Biology
IME Special Seminar: Antoine Georges
Quantum Materials: Bridging Physical Mechanisms, Simple Models and Realistic ComputationsQuantum Materials display competing phases with fascinating physical properties, which result from the multiple degrees of freedom in presence (charge, spin, orbital, lattice) and from strong electronic correlations. In this talk, I will show how computational methods aimed at the quantum many-body problem can be combined with realistic electronic structure methods in order to shed light on these physical properties, help identify relevant mechanisms and formulate simple effective models. This will be mostly illustrated by rare-earth nickelates, a family of materials displaying a metal-insulator transition which can be controlled by strain, gating or light, pulses.
The Tuesday JFI Seminar - Suri Vaikuntanathan, Department of Chemistry, University of Chicago
Non-equilibrium Pathways for Self Assembly and OrganizationNonequilibrium forces can drive specific and novel pathways to modulate self-assembly and organization. The close connection between energy dissipation and organization is particularly apparent in biology. Indeed, it has been demonstrated that nonequilibrium forces are crucial for the functioning of biochemical processes responsible for error correction, adaptation and timing of events in the cell cycle. However, unlike the behavior and characteristics of equilibrium systems, where no energy is dissipated, general principles governing fluctuations about a steady state or the steady state itself in far-from-equilibrium conditions are just being discovered. In my talk, I describe how tools from non-equilibrium statistical mechanics can be used to direct self assembly far-from-equilibrium, engineer novel spatiotemporal correlations in active liquids, and finally support properties such as ultra sensitivity in non-equilibrium biochemical networks. These results provide a framework for uncovering fundamental design principles of organization in non-equilibrium chemical and biological processes.
For further information please contact Brenda Thomas at 773-702-7156 or by email at email@example.com. You may contact the Host, Aaron Dinner at 773-702-2330 or via email to firstname.lastname@example.org.
Polina Anikeeva, PhD, MatSci and Eng, MIT
Probing Neural Function with Electronic, Optical & Magnetic MaterialsMammalian nervous system contains billions of neurons that exchange electrical, chemical and mechanical signals. Our ability to study this complexity is limited by the lack of technologies available for interrogating neural circuits across their diverse signaling modalities without inducing a foreign-body reaction. My talk will describe neural interface strategies pursued in my group aimed at mimicking the materials properties and transduction mechanisms of the nervous system. Specifically, I will discuss (1) Fiber-based probes for multifunctional interfaces with the brain and spinal cord circuits; (2) Magnetic nanotransducers for minimally invasive neural stimulation; and (3) Active scaffolds for neural tissue engineering and interrogation.
Fiber-drawing methods can be applied to create multifunctional polymer-based probes capable of simultaneous electrical, optical, and chemical probing of neural tissues in freely moving subjects. Similar engineering principles enable ultra-flexible miniature fiber-probes with geometries inspired by nerves, which permit simultaneous optical excitation and recording of neural activity in the spinal cord allowing for optical control of lower limb movement. Furthermore, fiber-based fabrication can be extended to design of scaffolds that direct neural growth and activity facilitating repair of damaged nerves.
Molecular mechanisms of action potential firing inspire the development of materials-based strategies for direct manipulation of ion transport across neuronal membranes. For example, hysteretic heat dissipation by magnetic nanomaterials can be used to remotely trigger activity of neurons expressing heat-sensitive ion channels. Since the alternating magnetic fields in the low radiofrequency range interact minimally with the biological tissues, the magnetic nanoparticles injected into the brain can act as transducers of wireless magnetothermal deep brain stimulation. Similarly, local hysteretic heating allows magnetic nanoparticles to disrupt protein aggregates associated with neurodegenerative disorders.
Professor Yossi Weizmann, University of Chicago
Synthetic Nucleic Acid Topology and Colloidal LEGO-Like Nanoparticles for Biological and Plasmonic Applications
Frederick A. Heberle, PhD, Biology & Soft Matter Oak Ridge National Laboratory
Lipid organization in complex biomimetic membranes: Insight from Scattering & SimulationThe 3-dimensional architecture of biological membranes has functional consequences for living cells. In the outer leaflet of the plasma membrane, lipids are thought to organize into ordered yet fluid domains, with diverse evidence supporting participation of these “rafts” in membrane processes including protein sorting and signaling. Cells also actively maintain an asymmetric distribution of different lipid types between the plasma membrane’s inner and outer leaflets, resulting in transmembrane differences in fluidity and charge density. Despite intense interest, the fundamental mechanisms controlling raft size and morphology, as well as coupling between leaflets of different composition, remain elusive. The precise determination of phase-separated and asymmetric bilayer structure is a crucial step toward a deeper understanding of these mechanisms. To this end, small-angle neutron and X-ray scattering are powerful biophysical tools for interrogating both lateral and transverse bilayer structure with sub-nanometer resolution. Molecular dynamics simulations probe further still, providing a glimpse of membrane organization with atomic detail. In this talk, I will describe new approaches for combining experimental and computational data to obtain a detailed structural picture of complex biomimetic membranes.
IME Seminar: Aaron Streets, University of California, Berkeley
Imaging and Sequencing Single CellsQuantitative cellular imaging with coherent Raman microscopy reveals morphological characteristics and chemical composition at the single-cell level. Meanwhile recent advances in high-throughput sequencing have enabled whole-transcriptome profiling of gene expression in single cells. Both measurements can uncover heterogeneity in cellular populations that would otherwise be obscured in ensemble measurement. Furthermore both imaging and gene expression profiling can be used to quantify cell state during differentiation. However, in order to infer the relationship between gene expression and morphological phenotypes, it is necessary to image and sequence the same single cell. We use a microfluidic platform to couple imaging and RNA sequencing of single cells and present recent developments on how to analyze large, multimodal, single-cell datasets.
Baruch Kanner, Hebrew University, Hadassah Medical School
Gating and Ion-Coupling by GAT-1, a GABA transporter from the Brain
Chiral waves from spinning tops: topology without long range order12:00 time to eat
12:15 time to listen and help
IME Seminar: Robert Seidel
Valence-Photoelectron and Auger-Emission Spectroscopy at the Solid-Liquid Interface
Special Seminar: Professor Yunho Lee, Department of Chemistry, KAIST
Small Molecule Activation of the Nickel Pincer Complexes
Kwang Seob Jeong, Department of Chemistry, Korea University
Magnetic Property of Colloidal Nanocrystals with Electrons in the Conduction BandThis seminar presents results on the magnetic property of the colloidal quantum dot with controlled electron doping and in the absence of any heterogeneous metal impurity, and its correlation with the optical property. Depending on the number of electrons, the magnetism can be switched from diamagnetism to paramagnetism, and vice versa. Furthermore, the intraband transition created by a cation exchange method, and the ultrafast intraband Auger process induced by multiphoton mid-IR irradiation will be discussed as well.
Simulating ricochet off of sand: Surprising behavior at low speed.Come at noon with food and conversations
Topic of the day at 12:15.
Special Seminar: Professor Alex Travesset, Iowa State University and Ames Laboratory
Geometry, Topology, and Nanoparticle Superlattice Structure
When the Hall effect throws you a curveEat: 12:00
Swerve with the curve: 12:15
Who choreographed my cell clusters?Eat: 12:00
solve mystery: 12:15
Molecular Tetris: Vapor Depositing to Enhanced Stabilitynoon: eat food
12:15 let the games begin.
IME Special Seminar: Phillip Szuromi, Senior Editor, Science
Scientific Publishing from the InsideI will give a brief overview of the mission of AAAS and the Science family of journals. I will then discuss how the review process works at Science, and how this has changed (and not changed) from the print to the internet era. Finally I will offer some thoughts on what we are looking for in a submission to help potential authors gauge the suitability of a submission.
Aaron Hoskins, PhD, Uwisc
Spliceosome Function and Structure
Molecular TherapeuticsCynthia Burrows, PhD
University of Utah
The Epigenetics of Guanine in G-Quadruplexes
Tarun Kapoor, PhD
Chemical Approaches to Dissect the Diverse Functions of Proteins in the AAA+ Superfamily
Jon Clardy, PhD
Harvard Medical School
Chemical Ecology and Molecular Therapeutics
Jason Gestwicki, PhD
University of California, San Francisco
Targeting Protein-Protein Interactions in Chaperone Networks
Nathanael Gray, PhD
Harvard Medical School
New Chemical Approaches to Drugging Oncogenic
Hening Lin, MD
Sirtuins and Novel PTMs in Cell Signaling and Cancer
Philip Cole, PhD
Johns Hopkins School of Medicine
Targeting Lysine Reversible Modifications with Designed Small Molecules
Prof. Liqiang Mai - State Key Laboratory of Advanced Technology for Materials Synthesis & Processing Wuhan University of TechnologyOne-dimensional nanomaterials can offer large surface area, facile strain relaxation upon cycling and efficient electron transport pathway to achieve high electrochemical performance. Hence, nanowires have attracted increasing interest in energy related fields. We designed the single nanowire electrochemical device for in situ probing the direct relationship between electrical transport, structure, and electrochemical properties of the single nanowire electrode to understand intrinsic reason of capacity fading. The results show that during the electrochemical reaction, conductivity of the nanowire electrode decreased, which limits the cycle life of the devices.1 We have fabricated hierarchical MnMoO4/CoMoO4 heterostructured nanowires by combining "oriented attachment" and "self-assembly".2 The asymmetric supercapacitors based on the hierarchical heterostructured nanowires show a high specific capacitance and good reversibility with a cycling efficiency of 98% after 1,000 cycles. Then, we designed the general synthesis of complex nanotubes by gradient electrospinning, including Li3V2(PO4)3, Na0.7Fe0.7Mn0.3O2 and Co3O4 mesoporous nanotubes, which exhibit ultrastable electrochemical performance when used in lithium-ion batteries, sodium-ion batteries and supercapacitors, respectively.3 In addition, we have successfully fabricated a field-tuned hydrogen evolution reaction (HER) device with an individual MoS2 nanosheet to explore the impact of field effect on catalysis.4 We also constructed a new-type carbon coated K0.7Fe0.5Mn0.5O2 interconnected nanowires through a simply electrospinning method. The interconnected nanowires exhibit a discharge capacity of 101 mAh g-1 after 60 cycles, when measured as a cathode for K-ion batteries.5 Our work presented here can inspire new thought in constructing novel one-dimensional structures and accelerate the development of energy storage applications.
Prof. Shaul Mukamel, Department of Chemistry & Department of Physics and Astronomy
Catching Conical Intersections in the Act; Ultrafast Multidimensional Spectroscopy with X-ray pulses and Quantum LightABSTRACT: Multidimensional spectroscopy uses sequences of optical pulses to study dynamical processes in complex molecules through correlation plots involving several time delay periods. Extensions of these techniques to the x-ray regime will be discussed. Ultrafast nonlinear x-ray spectroscopy is made possible by newly developed free electron laser and high harmonic generation sources. The attosecond duration of X-ray pulses and the atomic selectivity of core X-ray excitations offer a uniquely high spatial and temporal resolution. Stimulated Raman detection of an X-ray probe may be used to monitor the phase and dynamics of the nonequilibrium valence electronic state wavepackets created by e.g. photoexcitation, photoionization and Auger processes. Conical intersections (CoIn) dominate the pathways and outcomes of virtually all photophysical and photochemical molecular processes. Despite extensive experimental and theoretical effort CoIns have not been directly observed yet and the experimental evidence is being inferred from fast reaction rates and some vibrational signatures. Novel ultrafast X ray probes for these processes will be presented. Short X-ray pulses can directly detect the passage through a CoIn with the adequate temporal and spectral sensitivity. The technique is based on a coherent Raman process that employs a composite femtosecond/attosecond X-ray pulse to directly detect the electronic coherences (rather than populations) that are generated as the system passes through the CoIn. Diffraction of X- ray pulses can be used to image the transition charge densities associated with the electronic coherence.
Using the quantum nature of light in spectroscopy will be discussed. Strong coupling of molecules to the vacuum field of micro cavities can modify the potential energy surfaces thereby manipulating the photophysical and photochemical reaction pathways. The photonic vacuum state of a localized cavity mode can be strongly mixed with the molecular degrees of freedom to create hybrid field- matter states known as polaritons. Simulations of the non-adiabatic avoided crossing of sodium fluoride in a cavity which incorporate the quantized cavity field into the nuclear wave packet dynamics will be presented. Numerical results show how the branching ratio between the covalent and ionic dissociation channels can be strongly manipulated by the optical cavity. Host: Norbert Scherer, 2-7069 or via email at email@example.com. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or by email at firstname.lastname@example.org.
Yoav Lahini, Harvard University
Non-Monotonic Aging and Memory Retention in Disordered Mechanical SystemsI will describe the observation of slow relaxations, aging and memory effects - hallmarks of glassy dynamics – in the mechanical response of two disordered systems: thin sheets crumpled into a ball and elastic foams. In particular, I’ll report the observation of a non-monotonic aging response that can last many hours. I will then describe ongoing experiments that exploit the macroscopic nature of these systems to try and uncover the underlying mechanisms. The experimental results are in good agreement with a phenomenological framework recently used to describe observations of monotonic aging in several glassy systems. This suggests not only a general mechanism, but also that the non-monotonic behavior may be generic and that a-thermal, macroscopic systems can exhibit glassy behaviors.
The Tuesday JFI Seminar - Alan Aspuru-Guzik, Department of Chemistry & Chemical Biology, Harvard University
Billions and Billions of MoleculesMany of the challenges of the twenty-first century are related to molecular processes such as the generation and storage of clean energy, water purification and desalination. These transformations require a next generation of more efficient, chemically stable, and non-toxic materials. Chemical space, the space of all possible synthesizable molecules,is practicallyinfinite and promises to have relevant candidate functional molecules to address these
challenges. One of the main goals of my research group is to develop understanding and tools for the exploration chemical space in order to accelerate the discovery of organic materials. Our design cycle is sped up by the constant interaction of theoreticians and experimentalists, the use of high-throughput computational techniques,machine learning, and the development of specialized big data tools. We have had recent successes in theoretically predicting and experimentally confirming in record times top performers in the areas of organic electronics, organic flow batteries and organic lightemitting diodes. In this talk, I will discuss what I consider are the key factors related with a successful high-performance screening approach as illustrated by these three different applications. I will end by discussing the future prospects and challenges associated with developing appropriate metrics for the cartography of chemical space. Polina Navotnaya, 2-6066 or via email at email@example.com. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or by email at firstname.lastname@example.org.
Jaeger Fest Symposium
The World in a Grain of SandThe central theme of this symposium is the emergent collective behavior of many interacting particles and the way this behavior manifests across leng scales: from the self-assembly of nanoparticles to the formation of planets.
Jaeger Fest Symposium
MRSEC Tutorials for graduate students and postdocsThe central theme of this symposium is the emergent collective behavior of many interacting particles and the way this behavior manifests across leng scales: from the self-assembly of nanoparticles to the formation of planets.
Jacob Bean, University of ChicagoHost: Mel Shochet
IME Distinguished Colloquium Series: Daniel Loss
Spin Qubits in Semiconductors: An Overview and OutlookThis talk will provide an overview of spin qubits in semiconducting nanostructures such as quantum dots and nanowires for electron and hole spins from a theorist's point of view. Despite enormous experimental efforts in many labs worldwide over the last twenty years, progress has been slow due to many challenges posed by complex material issues and the related many-body physics limiting the coherence of spin qubits. Nevertheless, the field has evolved steadily, in theory and experiment, and there is a strong belief in the community that the ultimate goal of building a powerful quantum computer most likely will be reached with spin qubits in semiconductor material which have the advantage of being inherently small and fast: In principle, it is possible to fit a billion spin qubits on a square centimeter and have them function at a clock speed of GHz. I will mention recent development and challenges for implementing surface code structures, in particular for Si or Ge hole-spin qubits in combination with superconducting striplines. If time permits, I will mention some recent theoretical ideas on hybrid systems which aim at combining topological qubits, such as Majorana fermions and parafermions, with spin qubits.
Cary Forest, Department of Physics, University of Wisconsin
Energy Transformation between Forms in the Big Red Plasma BallAstrophysical plasma are often characterized by quasi-stationary magnetized plasmas which both pressure dominated and flow dominated, and yet still behave as ideal plasmas with fluid and magnetic Reynolds numbers being large so that magnetic fields are frozen into the flowing, often turbulent plasma. The Big Red Plasma Ball is a flexible user facility designed to study a range of astrophysically relevant plasma processes in this unique regime, and to explore novel geometries and flows that mimic astrophysical systems. A multi-cusp magnetic bucket constructed from strong samarium cobalt permanent magnets now confines a 10 m3, fully ionized, magnetic-field-free plasma in a spherical geometry. Plasma parameters of Te ~5 to 20 eV and densities of ~1011 to 5 x 1012 cm-3 provide an ideal testbed for a range of astrophysical experiments, including self-exciting dynamos, plasma accretion via the magneto-rotational instability [MRI], collisionless magnetic reconnection, jet stability, stellar winds and more. This talk will describe the unique capabilities of BRPB, along with several experiments, in both operating and planning stages, that illustrate its possibilities. References: 1. C.B. Forest et al., J. Plasma Phys. 81, 345810501 (2015). 2. C. Cooper et al., Phys. Plasmas, 21, 013505 (2015).
The Tuesday JFI Seminar - Matteo Cargnello, Chemical Engineering Department, Stanford University
Tackling Big Challenges Using Tiny CrystalsABSTRACT: The understanding that fossil fuels are not endless and that their extensive use is causing irreversible climate changes prompted us to realize that we are in urgent need of sustainable energy generation processes, energy vectors, and solutions to reduce pollution and greenhouse gas emissions. Despite replacing fossil fuels while maintaining or improving the current standards of living with a growing population is one of the biggest challenges that we have to face, the solution might lie in tiny pieces of matter: nanocrystals. Nanocrystals have been known for a long time but it is only recently that we have been able to better study and control their properties. The advent of nanotechnology and its associated tools allowed indeed to manipulate the composition, size, shape, functionalization and assembly of nanocrystals and to create nanoarchitectures and macroscopic devices with novel properties and unrivaled performance. In this talk, the use of uniform and tailored nanocrystals for energy and environmental applications will be presented, with emphasis on how to precisely control the nanostructures to understand and exploit interactions between well defined building blocks. Applications include hydrogen generation through photocatalysis, reduction of methane emissions, pollution control, and fundamental understanding of reaction mechanisms. It is expected that advancements in the preparation and use of these tiny crystals can bring immense benefit for making big challenges more approachable. Host: Dmitri Talapin, 4-2607 or via email at email@example.com. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or by email at firstname.lastname@example.org.
Closs Lecture-Martyn Poliakoff, University of Nottingham
Andrew Ferguson, PhD, UIUC Materials Science and Engineering Department
Machine learning in soft and biological materials: Engineering self-assembling colloids and viral phase behaviorData-driven modeling and machine learning have opened new paradigms and opportunities in the understanding and design of soft and biological materials. Colloidal particles with tunable anisotropic surface interactions are of technological interest in fabricating soft responsive actuators, biomimetic polyhedral encapsulants, and substrates for high-density information storage. In the first part of this talk, I will describe our applications of nonlinear manifold learning to determine low-dimensional "assembly landscapes" from computer simulations and experimental particle tracking data for self-assembling patchy colloids. These landscapes connect colloid architecture and prevailing conditions with emergent assembly behavior, informing how to engineer the stability and accessibility of desired aggregates. Empirical models of viral fitness present a means to rationally design antiviral therapeutics by revealing vulnerabilities within the viral proteome. In the second part of this talk, I will discuss the translation of clinical sequence databases into spin glass models of viral fitness that reveal an interesting connection with statistical thermodynamics in which a data-driven fitness model of HIV admits an "error catastrophe" – mutational meltdown of the viral quasispecies induced by an elevated mutation rate – isomorphic to a first order phase transition. Our work informs new antiviral control strategies and provides a rationale for why HIV can live on the precipice of the error catastrophe with impunity.
Erez Berg, University of ChicagoHost: Philippe Guyot-Sionnest
Sophie Martin, PhD, University of Lausanne
How to mate once and only once: Yeast gamete fusion rapidly reconstitutes a bi-partite transcription factor to block re-fertilization
Stuart Rowan, The University of Chicago
Using Dynamic Chemistry to Access Stimuli-Responsive and Adaptive MaterialsThe dynamic bond can be defined as any class of bond that selectively undergoes reversible breaking and reformation, usually under equilibrium conditions. The incorporation of dynamic bonds (which can be either covalent or non-covalent) allows access to structurally dynamic polymers. Such polymers can exhibit macroscopic responses upon exposure to an environmental stimulus, on account of a rearrangement of the polymeric architecture. In such systems, the nature of the dynamic bond not only dictates which stimulus the material will be responsive to but also plays a role in the response itself. Thus, such a design concept represents a molecular level approach to the development of new stimuli-responsive materials. We have been interested in the potential of such systems to access new material platforms and have developed a range of new mechanically stable, structurally dynamic polymer films that change their properties in response to a given stimulus, such as temperature, light or specific chemicals. Such adaptive materials have been targeted toward applications that include healable plastics, responsive liquid crystalline polymers, chemical sensors, thermally responsive hydrogels, shape memory materials and mechanically dynamic biomedical implants. Our latest results in this area will be discussed.
The Tuesday JFI Seminar - Mohammad Hafezi, Joint Quantum Institute, University of Maryland
Topological Photonics: From Classical to QuantumThere are tremendous efforts underway to better understand systems with topological features --- global properties that are not discernible locally. The best-known examples are quantum Hall effects in electronic systems, where insensitivity to local properties manifests itself as conductance through edge states that are insensitive to defects and disorder. In this talk, I demonstrate how similar physics can be observed for photons; specifically, how various quantum Hall Hamiltonians can be simulated in an optical platform. I review the observation of topological photonic edge states using silicon-on-insulator technology, measurement of the associated topological invariants and our recent advances in studying the quantum transport of such structures. Furthermore, the addition of optical nonlinearity to this system provides a platform to implement fractional quantum Hall states of photons and anyonic states that have not yet been observed. More generally, the application of these ideas can lead to the development of optical devices with topological protection for classical and quantum information processing.
Stephen J. Lippard: Massachusetts Institute of Technology
Understanding and Improving Platinum Anticancer Drugs
Dmitri Feldman, Brown University
Particle-hole symmetry without particle-hole symmetry in the quantum Hall effect at ν = 5/2Numerical results suggest that the quantum Hall effect at the filling factor 5/2 is described by the Pfaffian or anti-Pfaffian state in the absence of disorder and Landau level mixing. Those states are incompatible with the observed transport properties of GaAs heterostructures, where disorder and Landau level mixing are strong. We show that the recent proposal of a PH-Pfaffian topological order by D. T. Son is consistent with all experiments. The absence of the particle-hole symmetry at the filling factor 5/2 is not an obstacle to the existence of the PH-Pfaffian order since the order is robust to symmetry breaking
Anthony Hyman, PhD, MPI Molecular Cell Biology and Genetics, Dresden
Biomolecular condensates: Organizers of cellular biochemistry
Danna Freedman:Northwestern University
Applying Inorganic Chemistry to Challenges in Physics
the faster you run, the less you rememberEat 12:00 noon
Joe Incandela, University of California,Santa Barbara/CERN
Zachariasen Lecture: "From the Higgs to dark matter: the search for the underlying code of our universe"
Lee Lecture: Professor Matthew Rosseinsky, University of Liverpool
Beyond the unit cell: control of function by local structure and dynamics from fuel cell electrodes to metal-organic frameworks
Luca Delacretaz, Stanford University
Transport with translational order and bad metalsI will present a hydrodynamic theory of weakly disordered electronic systems with fluctuating or static translational order, such as charge/spin density waves or Wigner crystals. This hydrodynamic approach leads to universal expressions for low frequency ac conductivities and viscosities. I will argue that similar ac conductivities are observed experimentally in a variety of bad metals, and conjecture that such materials have short range fluctuating charge order.
Jeremy England, MIT
Emergent Fine-tuning to Environment in a Complex Chemical reactionThe equilibrium steady state of an undriven mixture of reacting chemical species is uniquely determined by the free energy. Once external environmental drives are introduced, however, steady-state concentrations may deviate from these equilibrium values via sustained absorption and dissipation of work. From a physical standpoint, the living cell is a particularly intriguing example of such a nonequilibrium system, because the environmental work sources that power it are relatively difficult to access – only the proper orchestration of many distinct catalytic actors leads to a collective behavior that is competent to harvest and exploit available metabolites. Here, we study the dynamics of an in silico chemical network with random connectivity in a driven environment that only makes strong chemical forcing available to rare combinations of concentrations of different molecular species. We find that the long-time dynamics of such systems biased towards the spontaneous extremization of forcing, so that the molecular composition converges on states that exhibit exquisite fine-tuning to available work sources.
Lee Lecture: Prof. Matthew Rosseinsky, University of Liverpool
Design of Advanced Materials?
Lukasz Fidkowski, Stony Brook University
Chiral phases in Floquet quantum systems
Alex Miller: University of North Carolina at Chapel Hill
Cation-Responsive Pincer-Crown Ether Complexes for Tunable Catalysis
1st Annual UChicago MRSEC SymposiumLearn about ongoing work in the Materials Research Center!
Explore new collaborations & research directions!
GCIS 3rd Floor Atrium
11:30am -1:30pm: Lunch and Poster Session
1:30pm - 3:00pm: IRG 1 – Dynamics of Soft Interfaces
& IRG 2 – Active Materials
3:00pm - 3:15pm: Coffee Break
3:15pm-4:45pm: IRG 3 – Engineering Quantum Materials & Seed Research – “Multifunctional Interfaces of Different Dimensionality” & “Multifunctional Porous Materials”
4:45pm: Wine and Cheese
Lisa Manning, Syracuse University
Jamming in biological tissuesHost: Sid Nagel
Philip Nelson, University of Pennsylvania
Old and new news about single-photon sensitivity in human visionOne often hears that human vision is “sensitive to single photons,” when in fact the faintest flash of light that can reliably be reported by human subjects is closer to 100 photons. Nevertheless, there is a sense in which the familiar claim is true. Experiments conducted long after the seminal work of Hecht, Shlaer, and Pirenne now allow a more precise, and in some ways even more remarkable, conclusion to be drawn about our visual apparatus. A simple model that incorporates both old news (response of single rod cells) and newer news (loss at the first synapse) can account in detail for both old and new psychophysical data.
The 2nd Tuesday JFI Colloquium - Eric Borguet - Department of Chemistry, Temple UniversityInterfacial water structure, which can be probed by vibrational sum-frequency generation (vSFG) spectroscopy, is key to many processes. Time-resolved vSFG shows that in the absence of surface charge (pH 2), water at silica surfaces exhibits significantly slower OH stretch vibrational relaxation (~600 fs) compared to bulk water. However, at charged silica surfaces (e.g., pH 6), bulk-like fast dynamics (~200 fs) are observed at low ionic strength. This decelerates to ~600 fs, with the addition of NaCl. In parallel, vSFG results demonstrated that silica interfacial water structure is most sensitive to cations at pH=6-8. Consequently, it is unclear whether the observed slowing of the vibrational dynamics is due to the reduction in Debye length, or because of changes in the local hydrogen bonding environment caused by the electrolyte and how this might depend on the identity of the ions. Additional spectroscopic and time-resolved vSFG experiments on aqueous Al2O3 interfaces shed light on the ongoing debate on the role of ions in interfacial water structure and whether the observed behavior is specific to silica/water interfaces or can be generalized to other systems. Philippe Guyot-Sionnest, 2-7461 or via email at email@example.com. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or by email at firstname.lastname@example.org.
Snir Gazit, University of California at Berkeley
Charged fermions coupled to Ising gauge fields: Symmetry breaking, confinement, and emergent Dirac fermions.Lattice gauge theories are ubiquitous in physics, describing a wide range of phenomena from quark confinement to quantum materials. At finite fermion density, gauge theories are notoriously hard to analyze due to the fermion sign problem. Here, we investigate the Ising gauge theory in 2+1 dimensions, a problem of great interest in condensed matter, and show that it is free of the sign problem at arbitrary fermion density. At generic filling, we find that gauge fluctuations mediate pairing leading to a transition between a deconfined BCS state to a confined BEC. At half-filling, a π-flux phase is generated spontaneously with emergent Dirac fermions. The deconfined Dirac phase, with a vanishing Fermi surface volume, is a non-trivial example of violation of Luttinger's theorem due to fractionalization. At strong coupling, we find a single continuous transition between the deconfined Dirac phase and the confined BEC, in contrast to the expected split transition.
Kharasch Memorial Lecture - Sir Shankar Balasubramanian, University of Cambridge
How large is the natural DNA alphabet?
Peter Littlewood, University of Chicago
Physics of SustainabilityHost: Mel Shochet
Daniel Scolnic, University of Chicago
Measuring the size of the Universe with Standard CandleAstrophysicists use standard candles, objects which have roughly the same luminosity, to infer distances to far-away parts of the universe. Standard candles of variable stars called ‘cepheids’ were used to discover the expanding universe, and standard candles of exploding stars called ‘supernovae’ were used to discover the accelerating universe. Together, these two standard candles can be used to measure the size of the universe. Interestingly, this measurement of the size of the universe recovered conflicts with measurements of the size of the universe from extrapolations of data from the Cosmic Microwave Background. I will go over how we make our measurement, from soup to nuts, and discuss how we can be confident in the accuracy of our values. I will then discuss different ways too explain the tension we see in the different sets of measurements, and possible new physics that may be on the horizon.
The 1st Tuesday JFI Colloquium - Benjamin Lev, Department of Physics and Applied Physics - Stanford University
New Tools for Exploring Nonequilibrium Quantum Many-Body PhysicsABSTRACT: The simulation of quantum systems using ultracold atomic gases—quantum simulation—may be viewed as the creation of novel quantum systems in their own right rather than the simulation of well-known models. Often these systems possess collective properties impossible to observe in the solid state. In particular, these gaseous systems provide unique testbeds for emergent physics, especially that out of equilibrium. We present two novel avenues of inquiry into quantum nonequilibrium physics: the creation of dissipative quantum spin glasses and quantum neural networks using atoms coupled to the photonic modes of a confocal optical resonator and the study of nonequilibrium quench dynamics in highly magnetic and strongly interacting gases. Besides investigating long-unresolved issues in statistical mechanics (i.e., the order of spin glasses and thermalization in closed quantum systems), the experimental directions discussed point to novel neuromorphic computational architectures relying on driven-dissipative quantum dynamics.Host: Jonathan Simon, 2-9661 or via email at email@example.com. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or by email at firstname.lastname@example.org.
Kharasch Memorial Lecture - Sir Shankar Balasubramanian, University of Cambridge
Decoding human genomes on a population scale
Dominic Else, University of California, Santa Barbara
Floquet Time Crystals: How time-translation symmetry protects phases of matterA "Floquet time crystal" is a phase of matter in a periodically driven (Floquet) system which spontaneously breaks discrete time-translation symmetry. They are an entirely new "non-thermal" phase of matter which cannot exist in undriven systems. In this talk, I will discuss the recent theoretical prediction and experimental observation of Floquet time crystals. Time-translation symmetry occupies a special role in physics, since its generator is the Hamiltonian itself. Nevertheless, the theoretical formulation of time crystals turns out to be *almost* the same as for other symmetry-breaking phases of matter. I will also consider phases of matter in which the discrete time-translation symmetry is not spontaneously broken but nevertheless protects non-trivial phases, which are the analogs of "symmetry-protected topological" and "symmetry-enriched topological" phases for other symmetries.
Jingyuan Chen, Stanford University
Exact Bose-Fermi Duality on 3D Euclidean LatticeRecently a conjectured Bose-Fermi duality in 3 spacetime dimensions has drawn much interest from both high energy and condensed matter communities. We prove this duality by constructing an exact duality on lattice and showing our exact duality reduces to the conjectured duality in the continuum limit. All steps are analytic, exact, and simple.
Qiu Wang, Duke University
Leveraging Chemistry for Biology and Therapy: – New amination strategies to access biologically important molecules
Cameron Reed, Alma College
The Manhattan Project: A Look at the Physics"Host: Henry Frisch
Andrew Kruse, PhD, Harvard Medical School
New approaches to investigate G protein-coupled receptor function
Lenka Zdeborova, CNRS & CEA, Saclay, France
Statistical physics approach to compressed sensing and generalized linear regressionBayesian inference and statistical physics are formally closely related. Therefore methodology and concepts developed in statistical physics to understand disordered materials such as glasses and spin glasses can be elevated to analyze models of in statistical inference. We will present this approach in a rather general setting that covers analysis of compressed sensing, generalized linear regression, and the perceptron - a kind of a single layer neural network. At the one hand, this approach leads to the approximate message passing algorithm that is gaining its place among other widely used regression and classification algorithms. At the other hand, the related analyses leads to identification of phase transitions in the performance of Bayes-optimal estimators. We will discuss relation between these phase transitions and algorithmic hardness, and in the case of compressed sensing we will show how this understanding leads to a design of optimal measurement protocols.
Based partly on "Statistical-physics-based reconstruction in compressed sensing" PRX 2012 and reviewed in "Statistical physics of inference: Thresholds and algorithms" Advances of Physics 2016.
Andy Borovik:University of California, Irvine
Synthetic Chemistry as a Window into Biology
JFI Seminar - Prof. David Cobden, Department of Physics, Washington University
"Electronic Phases and Phase Transitions in Van der Waals Monolayers"ABSTRACT: Atomically thin materials can host many kinds of electronic phases, some unique to the 2D limit. Our observations indicate the realization of a quantum spin Hall state, an excitonic insulator, superconductivity, and ferro- and antiferromagnetism in van der Waals monolayers. Unlike 3D solids, monolayers are amenable to surface probes and can be doped by electrostatic gating. We are thus investigating ways to induce transitions between these phases electrostatically. In WTe2 monolayers at low temperatures we observe a transition between a two-dimensional topological insulator and a bulk conducting phase as a function of gate voltage, representing a gate-controlled quantum phase transition.Host: Jiwoong Park, 4-3179 or via email to email@example.com. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or by email at firstname.lastname@example.org.
Cenke Xu, University of California, Santa Barbar
self-dual quantum critical points in 2+1 dimensions
Jennifer M. Heemstra: University of Utah
Harnessing Nucleic Acid Molecular Recognition and Self-Assembly for Biosensing and Biomolecular Imaging
Two dynamical interfaces walk into an IRG…
a recap of tuesday's idea session12:00 Eat real food
12:15 digest bloblets
Zoran Hadzibabic, University of Cambridge
Quantum gas in a boxHost: Cheng Chin
Anette Hosoi, MIT
Hydrodynamics of Hairy SurfacesFlexible slender structures in flow are everywhere. While a great deal is known about individual flexible fibers interacting with fluids, considerably less work has been done on fiber ensembles, such as fur or hair, in flow. These hairy surfaces are abundant in nature and perform multiple functions from thermal regulation to water harvesting to sensing. Motivated by these biological systems, we consider two examples of hairy surfaces interacting with flow: (1) air entrainment in the fur of diving mammals and (2) symmetry breaking in hairy micro-channels.
In the first example, we take inspiration from semi-aquatic mammals (such as fur seals, otters, and beavers) which have specially adapted fur that serves as an effective insulator both above and below water. Many of these animals have evolved pelts that naturally entrap air when they dive. This air: (1) provides additional insulation under water, (2) provides added buoyancy, and (3) facilitates water shedding when the animals resurface. In this study we investigate diving conditions and fur properties which amplify air entrainment in fur. In the second example, we consider a fundamental component in hydraulic systems, the flow rectifier. One of the simplest ways to generate asymmetry in these devices is with a ball valve in which flow is completely obstructed in one direction and free to flow in the other. In this work we seek a variation that: (1) allows the designer to modulate the relative resistances in the rectifier and (2) can be achieved with solid state components (i.e. no moving parts).
The Tuesday JFI Seminar - Monika Schleier-Smith, Department of Physics, Stanford University
"Echoes of Entanglement: from Quantum Metrology to Scrambling"ABSTRACT: In the quest to approach the fundamental Heisenberg Limit in precision measurements, central challenges are the generation and detection of highly entangled states. I will describe how both of these challenges can be mitigated by “echo spectroscopy,” a technique inspired by the Loschmidt echo, a paradigmatic probe of chaos. A key ingredient is to effectively reverse the flow of time in an interacting many-body system by switching the sign of the Hamiltonian. I will describe progress towards engineering spin models with non-local, switchable-sign interactions using cold atoms strongly coupled to light an optical cavity. Intriguingly, similar non-local interactions feature in models for understanding fundamental bounds on chaos and information scrambling derived from the study of black holes, opening prospects for investigating these bounds in the laboratory.Host: Jonathan Simon, 2-9661 or via email at email@example.com. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or by email at firstname.lastname@example.org.
Viviana Gradinaru, PhD, CALTECH
Optogenetic, tissue clearing, and viral vector approaches to understand and influence whole-animal physiology and behaviorWe develop & employ optogenetics, tissue clearing and viral vectors to gain new insights on circuits underlying locomotion, reward & sleep. I will discuss how bidirectional manipulation of mesopontine cholinergic cell bodies exerted opposing effects on locomotor behavior & reinforcement learning & how these effects were separable via limiting photostimulation to PPN cholinergic terminals in the ventral substantia nigra pars compacta or to the ventral tegmental area, respectively (Xiao et al, Neuron, '16). Genetically encoded tools that can be used to visualize, monitor, and modulate mammalian neurons are revolutionizing neuroscience. However, use of genetic tools in non-transgenic animals is often hindered by the lack of vectors capable of safe, efficient & specific delivery to the desired cellular targets. To begin to address these challenges, we have developed an in vivo Cre-based selection platform (CREATE) for identifying adeno-associated viruses (AAVs) that more efficiently transduce genetically defined cell populations (Deverman et al, Nature Biotechnology, '16). As a first test of the CREATE platform, we selected for viruses that transduced the brain after intravascular delivery and found a novel vector, AAV-PHP.B, that transduces most neuronal types and glia across the brain. We also demonstrate how whole-body tissue clearing can facilitate transduction maps of systemically delivered genes (Yang et al, Cell, '14; Treweek et al, Nature Protocols, '16) and how non-invasive delivery vectors can be used to achieve dense to sparse labeling to enable morphology tracing (unpublished). Since CNS disorders are notoriously challenging due to the restrictive nature of the blood brain barrier, the recombinant vectors engineered to overcome this barrier can enable potential future use of exciting advances in gene editing via the CRISPR-Cas, RNA interference and gene replacement strategies to restore diseased CNS circuits. In addition to control of neuronal activity we need feedback on how exactly the tissue is responding to modulation. We have worked on two related topics: optical voltage sensors and imaging of single molecule RNA in cleared tissue. We used directed evolution of opsins to make them better at reporting action potentials (Flytzanis et al, Nature Communications, '14). Changes in RNA transcripts can also report on activity history of brain circuits. Preserving spatial relationships while accessing the transcriptome of selected cells is a crucial feature for advancing many biological areas, from dev bio to neuroscience. We recently reported on methods for multi-color, multi-RNA, imaging in deep tissues. By using single-molecule hybridization chain reaction (smHCR), PACT tissue hydrogel embedding and clearing and light-sheet microscopy we detected single-molecule mRNAs in ~mm-thick brain tissue samples (Shah et al, Development, '16) and by rRNA labeling we mapped the identity & growth rate of pathogens in clinical samples (DePas et al,'16).
Closs Lecture-Professor Mostafa El-Sayed, Georgia Institute of Technology
Photothermal Therapy of Cancer in Cells and in Different Animals Using Gold Nano-Rods: A Progress Report
Roger Melko, Perimeter Institute
Machine Learning the Many-Body ProblemCondensed matter physics is the study of the collective behavior of infinitely complex assemblies of electrons, nuclei, magnetic moments, atoms or qubits. This complexity is reminiscent of the “curse of dimensionality” commonly encountered in machine learning. Despite this curse, the machine learning community has developed techniques with remarkable abilities to classify, characterize and interpret complex sets of data, such as images and natural language recordings. Here, we show that modern architectures for supervised learning, such as fully-connected and convolutional neural networks, can identify phases and phase transitions in a variety of condensed matter Hamiltonians. Readily programmable through open-source software libraries, neural networks can be trained to detect multiple types of order parameter, as well as highly non-trivial states with no conventional order, directly from raw state configurations sampled with standard Monte Carlo. Further, Monte Carlo configurations can be used to train a stochastic variant of a neural network, called a Restricted Boltzmann Machine (RBM), for use in unsupervised learning applications. We show how RBMs, once trained, can be sampled much like a physical Hamiltonian to produce configurations useful for estimating physical observables. Finally, we explore the representational power of quantum and classical RBMs, their role in deep learning, and its possible relationship to the renormalization group.
John Jewett: University of Arizona
Viral muses to inspire chemistry
Bloblets in your cells: what is their mission?12:00 Eat real food
12:15 digest bloblets
Steve Kivelson, Stanford University
Intertwined Order in Highly Correlated Electron FluidsHost: Paul Wiegmann
Minjung Ryu, PhD, Purdue
Language, Culture, and Learning: Implications for Interdisciplinary Research
Jonathan Simon, University of Chicago
Exploring Landau Levels in Curved SpaceI will present recent work realizing topological phases of photons, both in curved space, and in lattices. The talk will focus on our recent exploration of Landau levels on a conical surface, generated using a non-planar (twisted) optical resonator to induce a synthetic magnetic field for optical photons, and employed to validate the famous Wen-Zee action. I will then discuss recent results demonstrating strong photon-photon interactions mediated by resonator Rydberg-electromagnetically induced transparency (EIT), and techniques we are developing to assemble topological few-body states both photon-by-photon, and through microscopic devices engineered for photon thermalization. I will conclude with our recent observation of time-resolved helical edge dynamics in Z_2 topological circuit lattices, and a T-broken extension in the microwave domain using arrays of 3D cavities and circuit quantum electrodynamics techniques. This work showcases the unique possibilities for Hamiltonian engineering and control in the photonic sector, a provides a taste of upcoming breakthroughs in engineering quantum materials from photons.
The Tuesday JFI Seminar - Elisabeth Guazzelli, Aix Marseille Univ, CNRS, IUSTI, Marseille, France
Rheology of Dense Suspensions of Non-Colloidal ParticlesABSTRACT: Dense suspensions are materials with broad applications both in industrial processes (e.g. waste disposal, concrete, drilling muds, metalworking chip transport, and food processing) and in natural phenomena (e.g. flows of slurries, debris, and lava). Despite its long research history and its practical relevance, the mechanics of dense suspensions remain poorly understood. The major difficulty is that the grains interact both by hydrodynamic interactions through the liquid and by mechanical contact. These systems thus belong to an intermediate regime between pure suspensions and granular flows. We show that we can unify suspension and granular rheology under a common framework by transferring the frictional approach of dry granular media to wet suspensions of spherical particles. We also discuss non-Newtonian behavior such as normal-stress differences and shear-induced migration. Beyond the classical problem of dense suspension of hard spheres which is far from being completely resolved, there are also entirely novel avenues of study concerning more complex mixtures of particles and fluids such as those involving other types of particles (e.g. fibers) or non-Newtonian fluids (e.g. yield-stress fluids) that we will also address. Host: Heinrich Jaeger, 2-6074 or via email at email@example.com. Persons with a disability who may need assistance contact Brenda Thomas at 2-7156 or by email at firstname.lastname@example.org.
Matthew Lapa, UIUC
Electromagnetic response and anomalies in bosonic symmetry-protected topological phasesSymmetry-protected topological (SPT) phases, gapped phases of matter protected by the symmetry of a group G and possessing interesting boundary states, have been the focus of intense investigation for the past several years. While much is known about the classification and properties of these phases, especially in low dimensions, it is still a challenge to understand the physical properties which characterize a given (interacting) SPT phase in a general dimension. In this talk I will explain how a field-theoretic description of bosonic SPT phases in terms of nonlinear sigma models (NLSMs) can be combined with the theory of gauged Wess-Zumino actions to study the electromagnetic response and anomalies of some bosonic SPT phases with U(1) symmetry in all dimensions. In particular, I will present a calculation of the topological part of the electromagnetic response of bosonic integer quantum Hall (BIQH) states in odd spacetime dimensions and bosonic topological insulator (BTI) states in even spacetime dimensions. In addition, I will argue that the boundary of the BTI state exhibits a global anomaly similar to the parity anomaly of Dirac fermions in odd spacetime dimensions. This argument can be made precise for the boundary theory of the BTI state in two spacetime dimensions. If time allows, I will explain how the connection between gauged Wess-Zumino actions and equivariant cohomology can be used to prove that these results are robust against smooth, symmetry-preserving deformations of the target space of the NLSM used to describe these states.
Gregory T. Tietjen, PhD, Yale
A biophysical approach to engineering vascular targeted nanomedicine
Ribhu Kaul, University of Kentucky
Quantum phase transitions in square lattice SU(N) and SO(N) magnetsI will discuss the phases and phase transitions in some simple SU(N) and SO(N) quantum spin models, studied both using ideas from quantum field theory and with large scale numerical simulations.
James Morken, Boston College
New Strategies in Organic Synthesis Enabled by Catalytic Reactions of Organoboron Reagents
The 1st Tuesday JFI Colloquium - Mark G. Raizen - Department of Physics, University of Texas at Austin
From Maxwell’s Demon to Einstein’s Speed DemonABSTRACT: In this talk, I will describe two historical thought experiments in statistical mechanics and their experimental realization. Maxwell’s Demon was proposed by James Clerk Maxwell in 1871 as a way to reduce the entropy of gas-phase particles by means of an “intelligent creature with deft hands.” We have realized this thought experiment with a self-acting one-way wall for atoms, as originally suggested by Maxwell. This construction has been used to cool atoms, and for efficient isotope separation which will have important medical applications. In 1907, Albert Einstein predicted that Brownian motion should be ballistic on very short time scales, rather than diffusive. Einstein concluded that this instantaneous velocity would be impossible to measure in practice, a prediction that held for over 100 years. We have realized such a ‘speed demon’ by measuring the motion of micrometer beads held in optical tweezers, and have resolved the instantaneous velocity of a Brownian particle in air and in liquid. This system can be used to study the onset of irreversibility, the “arrow of time.”Host(s):Cheng Chin, 2-7192 or via email to email@example.com. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or by email at firstname.lastname@example.org.
Wolfgang Ketterle, MIT
New forms of matter with ultracold atoms: synthetic gauge fields and supersolidityHosts: Cheng Chin
Yimon Aye, Cornell
Stay On Target: Deconvoluting Mixed Redox Messages through Precision Redox Targeting
The Tuesday JFI Seminar - James F. Cahoon, Department of Chemistry, University of North Carolina - Chapel Hill
From Nanowires to Nanoplatelets: Designing Semiconductor Morphology so Form Follows FunctionSemiconductors are used in a vast array of modern technologies, including solar cells that convert sunlight into electricity and microprocessors that drive computers. They can be used to direct the flow of energy in devices or to convert energy from one form to another. These functions are enabled by the specific choice of material and composition. Shape, however, is another fundamental characteristic that can be used to encode functionality. Here, I will describe my group’s efforts to usenanometer-scale morphology as a strategy to encode novel photovoltaic, electronic, and optical properties in materials created by bottom-up methods. We chemically synthesize nanostructures, such as metal oxide particles and group IV nanowires, with precise morphology and composition, and we evaluate their physical properties using nanofabrication, spectroscopic, electrochemical, and computational methods. For instance, I will describe a strategy to create silicon nanowires with lithographic-like patterns, enabling applications ranging from photonic crystals to non-volatile memory. In addition, I will outline our efforts to design wide-bandgap photocathode materials for integration in solar fuels devices. The results yield insights into the synthesis, structure-function relationships, and technological applications of designed, bottom-up semiconductor nanomaterials. Host: Bozhi Tian; Contact him at 2-8749 or via email at email@example.com. Persons with a disability who may need assistance please contact Brenda Thomas at 2-7156 or by email at firstname.lastname@example.org.
Wheland Lecture - John P. Maier: University of Basel
Electronic Spectroscopy of C60+ and its Identification in Interstellar Space
The 2nd Tuesday JFI Colloquium - Hui Zhai, Tsinghua University, Institute for Advanced Study
Closs Lecture - Christopher Chang, University of California, Berkeley
Transition Metal Signaling in the Brain and Beyond
Moh El-Naggar, PhD, Depts of Physics and Astronomy, of Biological Sciences, and of Chemistry, University of Southern California
Far, Fast, & Surprising: Extracellular Electron Transport in Microbial Redox ChainsThe stepwise movement of electrons within and between molecules dictates all biological energy conversion strategies, including respiration and photosynthesis. With such a universal role across all domains of life, the fundamentals of ET and its precise impact on bioenergetics have received considerable attention, and the broad mechanisms allowing ET over small length scales in biomolecules are now well appreciated.
In what has become an established pattern, however, our planet’s oldest and most versatile organisms are now challenging our current state of knowledge. With the discovery of bacterial nanowires and multicellular bacterial cables, the length scales of microbial ET observations have jumped by 7 orders of magnitude, from nanometers to centimeters, during the last decade alone! This talk will take stock of where we are and where we are heading as we come to grips with the basic mechanisms and immense implications of microbial long-distance electron transport. We will focus on the biophysical and structural basis of long-distance, fast, extracellular electron transport by metal-reducing bacteria. These remarkable organisms have evolved direct charge transfer mechanisms to solid surfaces outside the cells, allowing them to use abundant minerals as electron acceptors for respiration, instead of oxygen or other soluble oxidants that would normally diffuse inside cells. From an environmental perspective, these microbes are major players in global elemental cycles. From a technological perspective, microbial extracellular electron transport is heavily pursued for interfacing redox reactions to electrodes in multiple renewable energy technologies.
But how can an organism transfer electrons to a surface many cell lengths away? What molecules mediate this transport? And, from a physics standpoint, what are the relevant length, time, and energy scales? We will describe new experimental and computational approaches that revealed how bacteria organize heme networks on outer cell membranes, and along the quasi-one-dimensional filaments known as bacterial nanowires, to facilitate long-range charge transport. Using correlated electron cryo-tomography and in vivo fluorescent microscopy, we are gaining new insight into the localization patterns of multiheme cytochromes along nanowires as well as the morphology and the formation mechanism of these structures. In addition, we will examine the fundamental limits of extracellular electron transport, down to microbial energy acquisition by single cells. These findings are shedding light on one of the earliest forms of respiration on Earth while unraveling surprising biotic-abiotic interactions.