Document Type
Article
Publication Date
1-1-2002
Abstract
We study the quantum dynamics of the center-of-mass momentum distribution for the populations of a cold gas with two-level system undergoing spontaneous decay and coupled to a Markovian thermal reservoir at arbitrary temperature. We derive the momentum-convolutionless coupled equations for momentum Fourier transform of the populations which can be easily solved numerically and analytically for a specific internal scheme and for zero-temperature cases. The time and momentum evolutions of the populations are obtained by inverse Fourier transform. The momentum spread and the center-of-mass entropy across one momentum dimension are computed and compared for different internal schemes, between zero-temperature and finite-temperature cases and between pi and sigma(+/-) transitions. For initial subrecoil momentum width, the sigma(+/-) transition displays a two-peak feature. Our results well describe the momentum spread dynamics of cold gas in thermal radiation at early: time and complement the results based on Fokker-Planck equation.
Keywords
Laser
Divisions
PHYSICS
Publication Title
Physical Review A
Volume
66
Issue
6
Additional Information
Department of Physics, Faculty of Science Building, University of Malaya, 50603 Kuala Lumpur, MALAYSIA