Implementation of Cavity Squeezing of a Collective Atomic Spin

Abstract

We squeeze unconditionally the collective spin of a dilute ensemble of laser-cooled ${}^{87}\mathrm{Rb}$ atoms using their interaction with a driven optical resonator. The shape and size of the resulting spin uncertainty region are well described by a simple analytical model [M. H. Schleier-Smith, I. D. Leroux, and V. Vuletić, arXiv:0911.3936 [Phys. Rev. A (to be published)]] through 2 orders of magnitude in the effective interaction strength, without free parameters. We deterministically generate states with up to 5.6(6) dB of metrologically relevant spin squeezing on the canonical ${}^{87}\mathrm{Rb}$ hyperfine clock transition. DOI: http://dx.doi.org/10.1103/PhysRevLett.104.073602 © 2010 The American Physical Society