Dynamics of Open Bosonic Quantum Systems in Coherent State Representation.pdfVIP

Dynamics of Open Bosonic Quantum Systems in Coherent State Representation D.A.R. Dalvit,1 G.P. Berman,1 and M. Vishik2 1 Theoretical Division, MS B213, Los Alamos National Laboratory, Los Alamos, NM 87545, USA 2Department of Mathematics, The University of Texas at Austin, Austin, TX 78712-1082, USA (Dated: February 1, 2008) We consider the problem of decoherence and relaxation of open bosonic quantum systems from a perspective alternative to the standard master equation or quantum trajectories approaches. Our method is based on the dynamics of expectation values of observables evaluated in a coherent state representation. We examine a model of a quantum nonlinear oscillator with a density-density interaction with a collection of environmental oscillators at finite temperature. We derive the exact solution for dynamics of observables and demonstrate a consistent perturbation approach. 6 PACS numbers: 03.65.Yz, 03.75.Gg, 07.79.Lh 0 0 2 I. INTRODUCTION systems. The method is a generalization of the well stud- n ied asymptotic theory for bosonic closed quantum sys- a tems [11] to the case of open dynamics. Such an approach J When a small quantum system interacts with an en- provides a method to derive exact, c-number, partial dif- vironment it undergoes irreversible processes such as re- 0