Semiclassical Klein–Kramers and Smoluchowski equations for the Brownian motion of a particle in an external potential

Autor: B. P. Mulligan, William T. Coffey, Yu. P. Kalmykov, Serguey V. Titov
Rok vydání: 2006
Předmět:
Zdroj: Journal of Physics A: Mathematical and Theoretical. 40:F91-F98
ISSN: 1751-8121
1751-8113
DOI: 10.1088/1751-8113/40/3/f02
Popis: The quantum Brownian motion of a particle in an external potential V(x) is treated using the master equation for the Wigner distribution function W(x, p, t) in phase space (x, p). A heuristic method of determination of diffusion coefficients in the master equation is proposed. The time evolution equation so obtained contains explicit quantum correction terms up to o(4) and in the classical limit, → 0, reduces to the Klein–Kramers equation. For a quantum oscillator, the method yields an evolution equation for W(x, p, t) coinciding with that of Agarwal (1971 Phys. Rev. A 4 739). In the non-inertial regime, by applying the Brinkman expansion of the momentum distribution in Weber functions (Brinkman 1956 Physica 22 29), the corresponding semiclassical Smoluchowski equation is derived.
Databáze: OpenAIRE