Master equation for quantum Brownian motion derived by stochastic methods
Abstract
The master equation for a linear open quantum system in a general environment is derived using a stochastic approach. This is an alternative derivation to that of Hu, Paz and Zhang, which was based on the direct computation of path integrals, or to that of Halliwell and Yu, based on the evolution of the Wigner function for a linear closed quantum system. We first show by using the influence functinal formalism that the reduced Wigner function for the open system coincides with a distribution function resulting from averaging both over the initial conditions and the stochastic source of a formal Langevin equation. The master equation for the reduced Wigner function can then be deduced as a FokkerPlanck equation obtained from the formal Langevin equation.
 Publication:

arXiv eprints
 Pub Date:
 March 2001
 arXiv:
 arXiv:grqc/0103037
 Bibcode:
 2001gr.qc.....3037C
 Keywords:

 General Relativity and Quantum Cosmology
 EPrint:
 10 pages, RevTeX. To appear in the proceedings of the 5th Peyresq meeting