Regensburg 2010 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 1: Statistical Physics (general) I
DY 1.4: Vortrag
Montag, 22. März 2010, 11:00–11:15, H47
Quantum master equations in phase space applied to the Brownian motion in a periodic potential: comparison of various kinetic models for Wigner’s function — Liam Cleary1, •William T. Coffey1, William J. Dowling1, Yuri P. Kalmykov2, and Serguey V. Titov3 — 1Trinity College Dublin, Ireland — 2Université de Perpignan, France — 3Russian Academy of Sciences, Russia
A comparison of the master equations for the time evolution of the Wigner distribution function W(x,p,t) in phase space (x,p) for various quantum kinetic models of dissipation is presented by considering the quantum Brownian motion of a particle in a cosine periodic potential V(x)=−V0 cos(x/x0). The dynamic structure factor, averaged spectrum of the structure factor and escape rate are evaluated for each model via matrix continued fractions in the manner customarily used for the classical Fokker-Planck equation. The escape rates so yielded are compared with that given analytically by the quantum-mechanical reaction rate solution of the Kramers turnover problem.