Enhancing the performance of an optical lattice clock with multiple atomic ensembles

The remarkable precision of optical atomic clocks enables new applications and can provide sensitivity to novel and exotic physics. In this talk I will explain the motivation and operating principles of a “multiplexed" strontium optical lattice clock, which consists of two or more atomic ensembles of trapped, ultra-cold strontium in one vacuum chamber. This miniature clock network enables us to bypass the primary limitations to standard comparisons between atomic clocks and thereby achieve new levels of precision.

I will present experimental results in which we make use of multiple atomic ensembles to perform enhanced phase estimation and demonstrate a reduced absolute instability of an optical lattice clock. I will also briefly present the results of a blinded, laboratory-based precision test of the gravitational redshift at the millimeter to centimeter scale that takes advantage of synchronous differential comparisons to enhance the sensitivity of the measurement while mitigating common-mode systematics. I will then present out progress towards a second-generation experimental apparatus that will enable precision measurements of the gravitational redshift at the meter-scale on a table top. And finally, I will discuss recent measurements demonstrating how we can use our apparatus to study and leverage the level structure of strontium in order to extend the achievable coherent clock interrogation time.