Squeezing of vacuum fluctuations via Zeeman coherence

Summary form only given. We suggest a promising way to obtain the squeezing of vacuum fluctuations. We study the interaction of linearly polarized light with atoms in a double-/spl Lambda/ configuration, where the two lower levels are Zeeman sublevels of the atomic ground state and the upper levels are the hyperfine components of the atomic excited state. In such systems, Kerr nonlinearity associated with the ac-Stark effect causes self-rotation of the elliptical polarization. At the same time when the linearly polarized light traverses such a medium, a squeezed vacuum is produced in the orthogonal polarization.