An exactly solvable model of the BCS-BEC crossover
Abstract
We discuss an integrable model of interacting Fermions in one dimension, that allows an exact description of the crossover from a BCS- to a Bose-like superfluid. This model bridges the Gaudin-Yang model of attractive spin 1/2 Fermions to the Lieb-Liniger model of repulsive Bosons. Using a geometric resonance in the one-dimensional scattering length, the inverse coupling constant varies from minus infinity to plus infinity while the system evolves from a BCS-like state through a Tonks gas to a weakly interacting Bose gas of dimers. We study the ground state energy, the elementary density and spin excitations, and the correlation functions. An experimental realization with cold atoms of such a one-dimensional BCS-BEC crossover is proposed.
Cite
@article{arxiv.cond-mat/0402448,
title = {An exactly solvable model of the BCS-BEC crossover},
author = {J. N. Fuchs and A. Recati and W. Zwerger},
journal= {arXiv preprint arXiv:cond-mat/0402448},
year = {2007}
}
Comments
corrected typos, minor modifications, submitted version