Casimir interaction among heavy fermions in the BCS-BEC crossover
Abstract
We investigate a two-species Fermi gas with a large mass ratio interacting by an interspecies short-range interaction. Using the Born-Oppenheimer approximation, we determine the interaction energy of two heavy fermions immersed in the Fermi sea of light fermions as a function of the s-wave scattering length. In the BCS limit, we recover the perturbative calculation of the effective interaction between heavy fermions. The p-wave projection of the effective interaction is attractive in the BCS limit while it turns out to be repulsive near the unitarity limit. We find that the p-wave attraction reaches its maximum between the BCS and unitarity limits, where the maximal p-wave pairing of heavy minority fermions is expected. We also investigate the case where the heavy fermions are confined in two dimensions and the p-wave attraction between them is found to be stronger than that in three dimensions.
Keywords
Cite
@article{arxiv.0811.1615,
title = {Casimir interaction among heavy fermions in the BCS-BEC crossover},
author = {Yusuke Nishida},
journal= {arXiv preprint arXiv:0811.1615},
year = {2009}
}
Comments
11 pages, 6 figures