Does the attractive Hubbard model support larger persistent currents than the repulsive one ?
Condensed Matter
2009-10-22 v1
Abstract
We consider a one-dimensional Hubbard model in the presence of disorder. We compute the charge stiffness for a mesoscopic ring, as a function of the size , which is a measure of the permanent currents. We find that for finite disorder the permanent currents of the system with repulsive interactions are larger than those of the system with attractive interactions. This counter intuitive result is due to the fact that local density fluctuations are reduced in the presence of repulsive interactions.
Cite
@article{arxiv.cond-mat/9411063,
title = {Does the attractive Hubbard model support larger persistent currents than the repulsive one ?},
author = {T. Giamarchi and B. S. Shastry},
journal= {arXiv preprint arXiv:cond-mat/9411063},
year = {2009}
}
Comments
14 pages; Revtex 3.0; 3 postscript figures uuencoded with uufiles