Increased atom-cavity coupling through cooling-induced atomic reorganization

Abstract

The strong coupling of atoms to optical cavities can improve optical lattice clocks as the cavity enables metrologically useful collective atomic entanglement and high-fidelity measurement. To this end, it is necessary to cool the ensemble to suppress motional broadening, and advantageous to maximize and homogenize the atom-cavity coupling. We demonstrate resolved Raman sideband cooling via the cavity as a method that can simultaneously achieve both goals. In 200 ms of Raman sideband cooling, we cool ^{171}Yb atoms to an average vibration number 〈n_{x}〉=0.23(7) in the tightly binding direction, resulting in 93% optical π-pulse fidelity on the clock transition ^{1}S_{0}→^{3}P_{0}. During cooling, the atoms self-organize into locations with maximal atom-cavity coupling, which will improve quantum metrology applications.