Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 19: Symposium Spin Effects in Semiconductors of Reduced Dimensionality

HL 19.5: Hauptvortrag

Dienstag, 26. Februar 2008, 12:30–13:00, ER 270

Transport in 2DEGs and Graphene: Electron Spin vs. Sublattice Spin — •Maxim Trushin and John Schliemann — Institute for Theoretical Physics University of Regensburg D-93040 Regensburg

Firstly, we present a model study of a curved two-dimensional electron gas (2DEG) [1] with Rashba spin-orbit (SO) interactions where for a certain relation between the SO coupling strength and curvature radius the tangential component of the electron spin becomes a conserved quantity for any spin-independent scattering potential [2]. This striking feature is exhibited by rolled-up 2DEGs and is not shared by their usual planar counterparts with Rashba SO interaction. Secondly, we focus on current-induced spin accumulation in a planar 2DEG with SO coupling of both the Rashba and the Dresselhaus type. This phenomenon sometimes also referred to as the kinetic magnetoelectric or inverse spin-galvanic effect [3] and shows for the system under study significant anisotropies. To investigate the spin responce to an in-plane electric field we rely on the exact analytical solution of the Boltzmann equation for electron spin and momentum [4]. The approach developed here is also applicable to the description of carrier transport in graphene [5] where low energy excitations have, with respect to the sublattice degree of freedom, a similar chiral structure as the usual 2DEG with Rashba SO interaction. [1] S.Mendach et al. Physica E v23, 274 (2004) [2] M.Trushin and J.Schliemann New J. Phys. v9, 346 (2007) [3] S.D.Ganichev et al. J. Magn. Magn. Mater. v300, 127 (2006) [4] M.Trushin and J.Schliemann Phys. Rev. B v75, 155323 (2007) [5] M.Trushin and J.Schliemann Phys. Rev. Lett. v99, 216602 (2007)