Speaker: Jack Dolde, Department of Physics Graduate Student
Abstract: Optical atomic clock improvement has advanced the fields of timekeeping, metrology, and quantum science. However, most current optical atomic clock stabilities are limited by the stability of the interrogating laser, rather than the atomic reference. In order to reduce the limiting effects of laser stability on precision metrology experiments with optical atomic clocks, we developed a multiplexing technique that allows us to simultaneously probe multiple atomic ensembles separated by 1 cm or less along the axis of a vertical 1-D optical lattice. Simultaneous probing of these ensembles allows common-mode rejection of laser frequency noise, allowing us to demonstrate a differential instability of 9.7(4)10^−18/√τ and a differential frequency uncertainty of 8.910^-20 after 3.3 hours of averaging. We then load 5 separate clock ensembles across 1 cm to create a miniature clock network, and subsequently tested the gravitational redshift effect predicted by general relativity across 1 cm of height difference. Currently, we are working to measure the natural linewidth of the 87Sr 1S0-3P0 clock transition through direct radiative decay observations.