Persistent Currents in Interacting Systems: Role of the Spin
Abstract
Persistent currents flowing through disordered mesoscopic rings threaded by a magnetic flux are investigated. Models of fermions with on-site interactions (Hubbard model) or models of spinless fermions with nearest neighbor interactions are considered on 2D cylinders with twisted boundary conditions in one direction to account for a magnetic flux. Self-consistent Hartree-Fock methods are used to treat the electron-electron interaction beyond first order. We show that the second harmonic of the current (which is relevant in the diffusive regime) is {\it strongly suppressed} by the interaction in the case of spinless fermions while it is {\it significantly enhanced} in the Hubbard model. Our data also strongly suggest that the reduction (increase) of this harmonic is related to a strong increase (reduction) of the spacial fluctuations of the charge density.
Keywords
Cite
@article{arxiv.cond-mat/9512153,
title = {Persistent Currents in Interacting Systems: Role of the Spin},
author = {Georges Bouzerar and Didier Poilblanc},
journal= {arXiv preprint arXiv:cond-mat/9512153},
year = {2007}
}
Comments
Latex file (5 pages), 7 postscript figures in uuencoded format included