Producing squeezed input states for an atomic clock using an optical cavity

Spin squeezing, the generation of collective states of atomic ensembles with reduced spin noise by exploiting non-classical correlations between particles, is a promising approach to overcoming the standard quantum limit set by projection noise of independent atoms. We present two implementations of spin squeezing in ensembles of ⁸⁷Rb confined within an optical resonator, and discuss some of the decoherence mechanisms, both technical and fundamental, that we encounter.