title: Embedding dissipation and decoherence in unitary evolution schemes.
abstract: Dissipation and decoherence, and the evolution from pure to mixed states in quantum physics, are handled through master equations for the density matrix. By embedding elements of this matrix in a higher-dimensional Liouville-Bloch equation, the methods of unitary integration are adapted to solve for the density matrix as a function of time, including the nonunitary effects of dissipation and decoherence. The input requires only solutions of classical, initial value time-dependent equations. Results are illustrated for a damped, driven two-level system.
authors.affiliation: Department of Physics and Astronomy, Louisiana State University, Baton Rouge 70803-4001, USA. arau@phys.lsu.edu
authors.forename: A R P
authors.initials: AR
authors.lastname: Rau
authors.forename: R A
authors.initials: RA
authors.lastname: Wendell