Regensburg 2010 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 19: Spin-controlled Transport I
HL 19.8: Talk
Tuesday, March 23, 2010, 11:30–11:45, H14
Interplay of Intrinsic and Extrinsic Mechanisms to the Spin Hall Effect in a Two-Dimensional Electron Gas — •Peter Schwab1 and Roberto Raimondi2 — 1Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany — 2CNISM and Dipartimento di Fisica, Università Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
In recent years spin-orbit interaction in semiconductors has attracted considerable attention due to its potential for controlling the spin degrees of freedom by electric fields. The spin Hall effect due to the structure inversion asymmetry (Rashba term) has been intensively studied, and it has been established that the spin Hall current vanishes in the static limit. The situation is different when both extrinsic and intrinsic effects are present. We provide a theory for this situation.
We derive drift-diffusion equations for the spin density in the presence of intrinsic spin-orbit coupling as well as skew scattering and side-jump contributions (extrinsic effects). We calculate the electric-field induced spin polarization and the spin Hall conductivity. First, the result by Edelstein for the spin polarization is strongly modified by the presence of the extrinsic spin-orbit interaction. Second, our expression for the spin Hall conductivity correctly reproduces the known limits. For realistic parameters the spin Hall conductivity is mainly due to the side-jump contribution.
[1] R. Raimondi, P. Schwab, EPL 87, 37008 (2009).