Atypical BCS-BEC crossover induced by quantum-size effects
Language
en
Article de revue
This item was published in
Physical Review A : Atomic, molecular, and optical physics [1990-2015]. 2012-09-12, vol. 86, n° 3, p. 033612 (1-7)
American Physical Society
English Abstract
Quantum-size oscillations of the basic physical characteristics of a confined fermionic condensate are a well-known phenomenon. Its conventional understanding is based on the single-particle physics, whereby the oscillations ...Read more >
Quantum-size oscillations of the basic physical characteristics of a confined fermionic condensate are a well-known phenomenon. Its conventional understanding is based on the single-particle physics, whereby the oscillations follow the size-dependent changes in the single-particle density of states. Here we present a study of a cigar-shaped ultracold superfluid Fermi gas, which demonstrates an important many-body aspect of the quantum-size effects, overlooked previously. The many-body physics is revealed in the atypical crossover from the Bardeen-Cooper-Schrieffer (BCS) superfluid to the Bose-Einstein condensate (BEC) induced by the size quantization of the particle motion. Quantized perpendicular spectrum results in the formation of single-particle subbands (shells) so that the aggregate fermionic condensate becomes a coherent mixture of subband condensates. Each time when the lower edge of a subband crosses the chemical potential, the BCS-BEC crossover is approached in this subband, and the aggregate condensate contains both the BCS and BEC-like components.Read less <
European Project
SCQSR
Origin
Hal imported