ISSN:
1572-9613
Keywords:
Quantum noise
;
correlation functions
;
long time tails
;
Brownian motion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The force and velocity correlation functions for a particle interacting with a bath are calculated within a model allowing for finite memory effects. The relevance of a Brownian picture is delineated in view of the respective behavior of these functions and appears fully inadequate below some cross-over temperature; then, the interplay between quantum and thermal fluctuations yields some long time tails on the same time scale for both correlation functions. The real space transient diffusion coefficient is found to exceed its asymptotic Einstein value for most times in that regime. The limiting case of an infinitely short memory time is also investigated and is seen to produce weak divergences on a time scale which is small as compared to the other characteristic times.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01010531
Permalink
