PME Quantum Special Seminar:  Shimon Kolkowitz, Ph.D. (University of Wisconsin-Madison)

11:00 am–12:00 pm

The remarkable precision of optical atomic clocks offers sensitivity to new and exotic physics through tests of relativity, searches for

dark matter, gravitational wave detection, and probes for beyond Standard Model particles. While much of optical clock research has

focused on improving absolute accuracy, many searches for new physics can be performed with relative comparisons between two


In this talk I will present recent experimental results in which we have demonstrated a “multiplexed” strontium optical lattice clock

consisting of two or more clocks in one vacuum chamber. In comparisons between two spatially separated atom ensembles in the same lattice

we observe atom-atom coherence times exceeding 26 seconds using correlated Ramsey spectroscopy andmeasure a fractional frequency shift at

a precision below one part in 10^19. We also realize a miniaturized clock network consisting of 6 atom ensembles, corresponding to 15 unique pairwise clock

comparisons performed simultaneously, each at a stability comparable to the previous record for clock comparisons. I will

discuss our ongoing campaign of systematics evaluation for a test of the gravitational redshift at the sub-cm scale, and the prospects

for future applications of the multiplexed optical lattice clock to searches for dark matter, novel tests of relativity, precision isotope

shift measurements to hunt for new forces, and demonstrations of entanglement-enhanced differential clock comparisons.

Event Type


May 24