Polarization-gradient-assisted subrecoil cooling: Quantum calculations in one dimension
1994; American Physical Society; Volume: 49; Issue: 6 Linguagem: Inglês
10.1103/physreva.49.4826
ISSN1538-4446
AutoresP. Marte, R. Dum, Richard Taïeb, P. Zoller, M. S. Shahriar, M. G. Prentiss,
Tópico(s)Quantum Information and Cryptography
ResumoWe present a fully quantum-mechanical analysis of laser cooling of an angular momentum ${\mathit{J}}_{\mathit{g}}$=1 to ${\mathit{J}}_{\mathit{e}}$=1 transition in a laser configuration consisting of two counterpropagating linearly polarized laser beams. The essential feature of this configuration is the coexistence of velocity-selective coherent population trapping (VSCPT) and polarization-gradient cooling. The role of polarization-gradient cooling is to provide (i) for short interaction times ``precooling'' of the initial momentum distribution and (ii) in the long-time limit ``confinement of velocities.'' This eventually leads to a larger number of atoms being captured in the dark state when compared with the schme of Aspect et al. [Phys. Rev. Lett. 61, 826 (1988)]. We find that the optimum parameter values for polarization-gradient cooling and VSCPT are in a completely different parameter regime: polarization-gradient cooling works best off resonance and for low intensities, while VSCPT works best on resonance. We can combine the advantages of polarization-gradient cooling and VSCPT in a scheme where we cycle in time between the optimum cooling parameters for both cooling mechanisms.
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