Relaxation of Schrödinger Cat States and Displaced Thermal States in a Density Operator Representation

Abstract

Damping of quantum superposition of displaced states such as a Schrödinger cat state and a displaced thermal state interacting with a thermal reservoir is studied in a density operator formalism. The master equation approach is employed and the solution is shown to be factorized to a thermal density operator and displacement operators. This formalism is applied to the cat generating experiment proposed by Brune et al. [Phys. Rev. A 45 (1992) 5193], and the field evolution is obtained analytically.