Document Type

Conference Proceeding

Publication Date



We first review the usefulness of the Wigner distribution functions (WDFs), associated with Lindblad and pre-master equations, for analysing 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 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.

Publication Source (Journal or Book title)

Journal of Optics B: Quantum and Semiclassical Optics