arXiv:quant-ph/0004057 · Physical Review A
Radiation pressure as a source of decoherence
Paulo A. Maia Neto, Diego A. R. Dalvit
Abstract
We consider the interaction of an harmonic oscillator with the quantum field via radiation pressure. We show that a ``Schr\"odinger cat'' state decoheres in a time scale that depends on the degree of ``classicality'' of the state components, and which may be much shorter than the relaxation time scale associated to the dynamical Casimir effect. We also show that decoherence is a consequence of the entanglement between the quantum states of the oscillator and field two-photon states. With the help of the fluctuation-dissipation theorem, we derive a relation between decoherence and damping rates valid for arbitrary values of the temperature of the field. Coherent states are selected by the interaction as pointer states.