Relativistic BCS-BEC crossover in a boson-fermion model
Abstract
We investigate the crossover from Bardeen-Cooper-Schrieffer (BCS) pairing to a Bose-Einstein condensate (BEC) in a relativistic superfluid within a boson-fermion model. The model includes, besides the fermions, separate bosonic degrees of freedom, accounting for the bosonic nature of the Cooper pairs. The crossover is realized by tuning the difference between the boson mass and boson chemical potential as a free parameter. The model yields populations of condensed and uncondensed bosons as well as gapped and ungapped fermions throughout the crossover region for arbitrary temperatures. Moreover, we observe the appearance of antiparticles for sufficiently large values of the crossover parameter. As an application, we study pairing of fermions with imbalanced populations. The model can potentially be applied to color superconductivity in dense quark matter at strong couplings.
Cite
@article{arxiv.nucl-th/0611097,
title = {Relativistic BCS-BEC crossover in a boson-fermion model},
author = {Jian Deng and Andreas Schmitt and Qun Wang},
journal= {arXiv preprint arXiv:nucl-th/0611097},
year = {2008}
}
Comments
ReVTex4, 19 pages, 10 figures; new chapter added about the case of imbalanced fermion populations; minor modifications to main part; references added