Dresden 2003 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 32: Spinabh
ängiger Transport II
HL 32.1: Vortrag
Mittwoch, 26. März 2003, 14:30–14:45, POT/81
Pumping spin with electrical fields — •Michele Governale1, Fabio Taddei2, and Rosario Fazio2 — 1Institut für Theoretische Festkörperphysik, Universität Karlsruhe, Germany — 2Scuola Normale Superiore, Pisa, Italy
The investigation of spin-dependent transport and its application to control electrical currents is at the foundation of Spintronics. The success in operating spin-based devices relies on the ability to produce and control spin currents. We show that spin currents can be obtained through adiabatic pumping by means of electrical gating only. This is possible by exploiting the tunability of the Rashba spin-orbit coupling in semiconductor heterostructures. We demonstrate the principles of this effect by considering a single-channel wire with a constriction. We also consider realistic structures, consisting of several open channels where subband mixing and disorder are present, and confirm our predictions. Two different ways to detect the spin-pumping effect, either using ferromagnetic leads or applying a magnetic field, are discussed. Furthermore, the spin-pumping phenomenon is described as a rectification of spin-dependent electric fields.