ENHANCED CHARGE AND SPIN CURRENTS IN THE ONE-DIMENSIONAL DISORDERED MESOSCOPIC HUBBARD RING

Article

关键词: METAL-INSULATOR-TRANSITION;    PERSISTENT CURRENTS;    MODEL;    CONDUCTIVITY;    LOCALIZATION;    EXPONENTS;    SINGLE;    LOOP;   

DOI  :  10.1103/PhysRevB.52.14809

来源: SCIE

【 摘 要 】

We consider a one-dimensional mesoscopic Hubbard ring with and without disorder and compute charge and spin stiffness as a measure of the permanent currents. For finite disorder we identify critical disorder strength beyond which the charge currents in a system with repulsive interactions are larger than those for a free system. The spin currents in the disordered repulsive Hubbard model are enhanced only for small U, where the magnetic state of the system corresponds to a charge-density wave pinned to the impurities. For large U, the state of the system corresponds to localized isolated spins and the spin currents are found to be suppressed. For the attractive Hubbard model we find that the charge currents are always suppressed compared to the free system at all length scales.

【 授权许可】

Free