Coulomb Promotion of Spin-Dependent Tunnelling

Abstract

We study transport of spin-polarized electrons through a magnetic single-electron transistor (SET) in the presence of an external magnetic field. Assuming the SET to have a nanometer size central island with a single electron level we find that the interplay on the island between coherent spin-flip dynamics and Coulomb interactions can make the Coulomb correlations promote rather than suppress the current through the device. We find the criteria for this new phenomenon -- Coulomb promotion of spin-dependent tunnelling -- to occur.Comment: 4 pages, 3 figures; The new version has a slightly modified title, 2 more figures, and an extended analysis of the (same) results obtaine