Quantum Fokker-Planck equation

The dynamics of quantum systems subject to dissipation is a subject of fundamental importance which has recently been of great interest due to its relation to macroscopic quantum phenomena, In particular the behaviour of the magnetic flux trapped in a SQUID is an example of this. The authors derive the quantum mechanical analogue of the Fokker-Planck equation which describes such systems. The major difference between the quantum and classical Fokker-Planck equations arises from the presence of a quantum mechanical memory term.