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arXiv · 0705.0648

Theory of a Magnetically-Controlled Quantum-Dot Spin Transistor

Daniel Urban·Matthias Braun·Jürgen König
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Abstract

We examine transport through a quantum dot coupled to three ferromagnetic leads in the regime of weak tunnel coupling. A finite source-drain voltage generates a nonequilibrium spin on the otherwise non-magnetic quantum dot. This spin accumulation leads to magnetoresistance. A ferromagnetic but current-free base electrode influences the quantum-dot spin via incoherent spin-flip processes and coherent spin precession. As the dot spin determines the conductance of the device, this allows for a purely magnetic transistor-like operation. We analyze the effect of both types of processes on the electric current in different geometries.

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Daniel Urban, Matthias Braun, Jürgen König. 2007-09-28. Theory of a Magnetically-Controlled Quantum-Dot Spin Transistor. https://doi.org/10.1103/physrevb.76.125306

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