Precision measurements with a multiplexed optical lattice clock*

The remarkable precision of optical atomic clocks offers sensitivity to new and exotic physics through novel tests of relativity, searches for dark matter, gravitational wave detection, and precision probes for beyond Standard Model particles and forces. While much of optical clock research has focused on improving absolute accuracy, many of the proposed searches for new physics can be performed with relative comparisons between clocks.

In this talk we 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 [1]. In intercomparisons between two spatially separated atom ensembles in the same lattice we observe atom-atom coherence times exceeding 26 s using correlated Ramsey spectroscopy and measure a fractional frequency shift at an imprecision below a part in 10¹⁹. 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. We 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, entanglement-enhanced quantum clocks, and precision isotope shift measurements to hunt for new forces.