Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 12: Spin controlled transport I
HL 12.8: Vortrag
Dienstag, 24. März 2009, 11:45–12:00, BEY 81
Controlable Manipulation of Structure Inversion Asymmetry (SIA) of Quantum Wells (QWs) by Shifting the Position of δ-doping Layer — •V. Lechner1, S.D. Ganichev1, V.V. Belkov2, P. Olbrich1, L.E. Golub2, S.A. Tarasenko2, D. Schuh1, W. Wegscheider1, D. Weiss1, and W. Prettl1 — 1Terahertz Center, University of Regensburg, Germany — 2A.F. Ioffe Physico-Technical Institute, Russian Academy of Sciences, St. Petersburg, Russia
We demonstrate that the growing of semiconductor QWs with various δ-doping layer positions accompanied by measurements of magnetogyrotropic photogalvanic effect (MGPE) [1] allows the controle of SIA. The MPGE originates from bulk inversion asymmetry (BIA) and SIA and therefore reflects their behaviour. We show that for a proper experimental geometry, currents measured along and perpendicular to B, are proportional to BIA and SIA, respectively. Our experiments prove that shifting the δ-doping layer from one side of the QW to the other results in a change of sign of the SIA-caused MPGE. Our measurements show that while nominally symmetrically doped (001)-grown structures have an essential structural asymmetry, (110)-grown structures are almost symmetrical. Our results allow the growth of perfectly symmetric structures without Rashba constant and structures with equal Rashba and Dresselhaus spin splittings. Experiments were carried out at room temperature on n-type GaAs quantum wells.
[1] V.V. Bel’kov, and S.D. Ganichev, review in Semicond. Sci. Technol. 23, 114003 (2008).