Regensburg 2007 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 23: Nanoelectronics II - Spintronics and Magnetotransport

TT 23.7: Vortrag

Donnerstag, 29. März 2007, 11:15–11:30, H19

Resonant spin polarization and spin current in a two-dimensional electron gas — •Mathias Duckheim and Daniel Loss — Department of Physics and Astronomy, University of Basel, CH-4056 Basel, Switzerland

A versatile scheme of spin control is electric dipole spin resonance (EDSR) where the radio-frequency fields driving the spins are electric[1], and not magnetic like in standard paramagnetic resonance. We present a theoretical study of EDSR in a disordered two-dimensional electron gas. We show that a very high spin polarization can be achieved in a sample where both Rashba and Dresselhaus spin orbit interactions are present rendering the spin splitting anisotropic. By choosing a particular geometry in a strong magnetic field the anisotropy of the spin splitting can be optimally exploited leading to a substantial enhancement of the spin susceptibility. Moreover, the generated spin polarization is intrinsically linked with an ac spin Hall current. The corresponding spin Hall conductivity displays a universal behavior in the high frequency limit and vanishes when the spin susceptibility is maximal. We show that the spin Hall current can be interpreted in terms of geometrical properties of the spin polarization.

[1] M. Duckheim and D. Loss, Nature Physics 2, 195 (2006)