Polarization Squeezing in Atomic Rubidium Vapour

Recently there has been debate regarding the possibility of using polarization self-rotation (PSR) in a thermal vapour cell as a mechanism for generating a squeezed vacuum state [1,2]. It has been claimed that the squeezing produced by this method is overwhelmed by atomic noise in the thermal vapour [2]. We present a new experimental study on the possibility to generate squeezing in this system and theoretical results that highlight the importance of the atomic ground state decoherence. \newline \newline [1] J. Ries, B. Brezger and A. I. Lvovsky, Pys. Rev. A 68, 025801 (2003). \newline [2] M. T. L. Hsu, G. Hetet, A. Peng, C. C. Harb, H.-A. Bachor, M. T. Johnsson, J. J. Hope, P. K. Lam, A. Dantan, J. Cviklinski, A. Bramati and M. Pinard, Phys. Rev. A 73, 023806 (2006).