Abstract: 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 and forces. 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 clocks. The use of correlated simultaneous differential clock comparisons relaxes the requirements on clock laser linewidth, experimental duty cycle, and control over the systematic effects limiting absolute frequency uncertainty, offering orders of magnitude potential gains in sensitivity to new physics.
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. In inter-comparisons 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 a precision below a 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. 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, and precision isotope shift measurements to hunt for new forces.
This seminar is supported with funds from the Korhammer Lecture Series