Spin Current and Current-Induced Spin Transfer Torque in Ferromagnet-Quantum Dot-Ferromagnet Coupled Systems

Abstract

Based on Keldysh's nonequilibrium Green function method, the spin-dependent transport properties in a ferromagnet-quantum dot (QD)-ferromagnet coupled system are investigated. It is shown the spin current shows quite different characteristics from its electrical counterpart, and by changing the relative orientation of both magnetizations, it can change its magnitude even sign. The current-induced spin transfer torque (CISTT) is uncovered to be greatly enhanced when the bias voltage meets with the discrete levels of the QD at resonant positions. The relationship between the CISTT, the electrical current and the spin current is also addressed.

21 pages, 8 figures

References in corpus (1)

• Kondo effect in quantum dots coupled to ferromagnetic leads

Cited by in corpus (7)

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• Transport through a double quantum dot system with non-collinearly polarized leads
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• Exchange effects on electron transport through single-electron spin-valve transistors
• Spin transport properties of a quantum dot coupled to ferromagnetic leads with noncollinear magnetizations
• Quantum Oscillations of Tunnel Magnetoresistance Induced by Spin-Wave Excitations in Ferromagnet-Ferromagnet-Ferromagnet Double Barrier Tunnel Junctions