We show that a thermal reservoir can effectively act as a squeezed reservoir on atoms that are subject to energy-level modulation. For sufficiently fast and strong modulation, for which the rotating-wave-approximation is broken, the resulting squeezing persists at long times. These effects are analyzed by a master equation that is valid beyond the rotating wave approximation. As an example we consider a two-level-atom in a cavity with Lorentzian linewidth, subject to sinusoidal energy modulation. A possible realization of these effects is discussed for Rydberg atoms.
@article{arxiv.1211.4378,
title = {Engineering a thermal squeezed reservoir by system energy modulation},
author = {Ephraim Shahmoon and Gershon Kurizki},
journal= {arXiv preprint arXiv:1211.4378},
year = {2013}
}