2003/11/12 by R. F. O'Connell
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1088/1464-4266/5/3/369
published as J.Optics B 5, S349(2003)
arxiv created 2003/11/12 · arxiv updated 2009/12/01
We first review the usefulness of the Wigner distribution functions (WDF), associated with Lindblad and pre-master equations, for analyzing a host of problems in Quantum Optics where dissipation plays a major role, an arena where weak coupling and long-time approximations are valid. However, we also show their limitations for the discussion of decoherence, which is generally a short-time phenomenon with decay rates typically much smaller than typical dissipative decay rates. We discuss two approaches to the problem both of which use a quantum Langevin equation (QLE) as a starting-point: (a) use of a reduced WDF but in the context of an exact master equation (b) use of a WDF for the complete system corresponding to entanglement at all times.