Tuning the spin Hall effect in a two-dimensional electron gasR. Raimondi1 and P. Schwab2
1 CNISM and Dipartimento di Fisica “E. Amaldi", Università Roma Tre - 00146 Roma, Italy, EU
2 Institut für Physik, Universität Augsburg - 86135 Augsburg, Germany, EU
received 8 June 2009; accepted in final form 27 July 2009; published August 2009
published online 27 August 2009
We provide a theoretical framework for the electric field control of the electron spin in systems with diffusive electron motion. The approach is valid in the experimentally important case where both intrinsic and extrinsic spin-orbit interaction in a two-dimensional electron gas are present simultaneously. Surprisingly, even when the extrinsic mechanism is the dominant driving force for spin Hall currents, the amplitude of the spin Hall conductivity may be considerably tuned by varying the intrinsic spin-orbit coupling via a gate voltage. Furthermore we provide an explanation for the mechanism giving rise to the experimentally observed out-of-plane spin polarization in a (110) GaAs quantum well.
72.25.-b - Spin polarized transport.
72.25.Rb - Spin relaxation and scattering.
© EPLA 2009