Physical Review A

Exact density-matrix calculations for simple open systems

Matthew J. Collett

Published Sep 1, 1988• 62 citations

Abstract

Explicit density-matrix solutions are obtained for several simple open quantum systems without the usual trace being taken over the thermal bath. This is achieved using a representation of the density matrix in terms of the dynamic operators of the system. The results are compared with those from conventional reduced calculations. Different types of irreversible behavior are found, and the implications of this distinction for models of quantum measurement are considered.

DOI: 10.1103/physreva.38.2233

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