Regensburg 2007 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 23: Spin controlled transport II
HL 23.3: Vortrag
Dienstag, 27. März 2007, 14:30–14:45, H14
Bulk inversion and structure inversion asymmetry in (110) semiconductor quantum wells — •P. Olbrich1, V. V. Belkov1,2, D. Schuh1, W. Wegscheider1, W. Prettl1, and S. D. Ganichev1 — 1Faculty of Physics, University of Regensburg, 93040, Regensburg, Germany — 2A.F. Ioffe Physico-Technical Instituete, Russian Academy of Sciences, 194021 St. Petersburg, Russia
Quantum well structures prepared on (110)-oriented GaAs substrates are interesting for spintronics because of considerably longer spin relaxation times compared to (001)-oriented QWs. This is due to vanishing Rashba spin splitting in symmetrically grown (110)-oriented QWs. In asymmetric QWs the advantage of long spin relaxation times fades away. Here we demonstrate that the recently observed magneto-gyrotropic effect (MPGE) [1] provides a simple and direct access to symmetry properties of QWs. We show that excitation of symmetric (110)-oriented QWs with THz radiation results in the MPGE only for the magnetic field aligned parallel to growth direction while it vanishes for an in-plane magnetic field. For asymmetric QWs even the in-plane magnetic field causes an electric current whose strength increases with rising degree of asymmetry. Our measurements show that for (110)-grown QWs it is sufficient to have symmetrical doping from the both sides of QWs in order to exclude Rashba spin-splitting.
[1] S.D. Ganichev, V.V. Bel’kov, S.A. Tarasenko, S.N. Danilov, S. Giglberger, Ch. Hoffmann, E.L. Ivchenko, D. Weiss, W. Wegscheider, Ch. Gerl, D. Schuh, J. Stahl, J. De Boeck, G. Borghs, and W. Prettl, Nature Physics (London) 2, 609 (2006).