Persistent currents in interacting electronic systems
Abstract
Persistent currents in disordered mesoscopic rings threaded by a magnetic flux are calculated using exact diagonalization methods in the one-dimensional (1D) case and self-consistent Hartree-Fock treatments for two dimensional (2D) systems. For multichannel systems, a comparative study between models of spinless or spinfull (Hubbard) fermions has been done. First, it is shown that a purely one-dimensional model can not reproduce the correct order of magnitude of the observed currents. For 2D systems, going beyond first order pertubative calculations, we show that the second harmonic of the current is {\it strongly suppressed} in the case of spinless fermion models but {\it significantly enhanced} for the Hubbard model. This reduction (resp. increase) of the second harmonic is related to a strong increase (resp. reduction) of the spacial charge density fluctuations. Our work underlines the important role of the spin degrees of freedom in the persistent currents.
Cite
@article{arxiv.cond-mat/9605188,
title = {Persistent currents in interacting electronic systems},
author = {Georges Bouzerar and Didier Poilblanc},
journal= {arXiv preprint arXiv:cond-mat/9605188},
year = {2008}
}
Comments
Invited paper to be published in Proceedings of Les Recontres de Moriond "Fermions Corr\'el\'es et Transport dans les syst\`emes M\'esoscopiques" 13 postscript files of the figures are included