Spin-dependent transport through an interacting quantum dot
Abstract
Using Anderson model, we study the nonequilibrium spin transport through an interacting quantum dot containing two spin levels coupled to magnetic electrodes. Different from the conventional Kondo problem with normal metal electrodes, the characteristics induced by the strong electronic correlation are sensitive to the relative magnetization of the two magnetic electrodes, namely, the parallel or antiparallel configuration. In this work a formula for spin-dependent current is obtained and is applied to discuss the linear conductance and magnetoresistance in the Kondo regime. We show that the Kondo resonance and the correlation-induced spin splitting of the dot levels may be systematically controlled by internal magnetization of the electrodes. As a result, when the electrodes are in parallel magnetic configuration, the linear conductance appears as a spin-resolved double-peak structure, wherein the main peak is dominated by the up-spin electrons while the side peak is due to the down spin electrons. A net magnetic moment emerges in the quantum dot due to spin accumulation effect. Furthermore, the presence of the spin-flip process caused by spin-orbit coupling in the dot splits the Kondo resonance into three peaks and tends to smear out the spin filtering effect. We also find that the linear magnetoresistance is significantly enhanced in the empty orbital regime where the dot level is higher than the chemical potential of the electrodes.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2003
- Bibcode:
- 2003APS..MARP30012Z