This means that is essentially the density matrix put into normal order.

If the state is given by a density matrix , .

The density matrix can be shown to transform to the interaction picture in the same way as any other operator.

However, it still is possible to associate a density matrix.

The role which was originally reserved for the quantities is thus taken over by the density matrix of the system S.

It is possible to carry out the fitting of a physical density matrix on the measured data even for large systems.

A quantum mechanical ensemble in general is described by a density matrix.

In general, a quantum state is described by a density matrix.

One of these is the use of the density matrix, and its associated master equation.

It has been shown that the density matrix for any state of light can be written as: