Phase Space Description

Abstract

In general, a full description of the state of the electromagnetic field is given by the density operator. However, there are various ways in which the field can be described by complex functions of α. These methods are of considerable practical interest, since one is dealing with functions rather than operators. The most common representations in phase space are the Glauber distribution, and the Q and Wignerrepresentations. The Wigner distribution is the one that resembles more closely the classical probability. On the other hand, the P-distribution originates from representing the density operator as an ensemble of coherent states and the Q-representation is a description of the density matrix via its diagonal elements, again, in a coherent state basis.