Spin squeezing of an ensemble of N atoms in a high-Q cavity is shown to be enhanced by continuous measurement of photons in the cavity. A degree of spin squeezing proportional to N^{-1/3} is attained as a quasi-steady state over a broad set of initial states of the atoms and photons.
@article{arxiv.cond-mat/0304127,
title = {Measurement-induced spin squeezing in a cavity},
author = {Hiroki Saito and Masahito Ueda},
journal= {arXiv preprint arXiv:cond-mat/0304127},
year = {2009}
}