Dresden 2011 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 3: III-V-Compounds: GaAs and related Materials
HL 3.2: Talk
Monday, March 14, 2011, 10:30–10:45, POT 151
Electron g-Factor Anisotropy in Symmetric (110)-oriented GaAs/AlGaAs Quantum Wells — •Jens Hübner1, Huynh Thanh Duc3, Sergej Kunz1, Stefan Oertel1, Michal Pochwala3, Dieter Schuh2, Thorsten Meier3, and Michael Oestreich1 — 1Institute for Solid State Physics, Leibniz Universität Hannover, Appelstr. 2, D-30167 Hannover, Germany — 2Institute for Experimental and Applied Physics, Universität Regensburg, D-93040 Regensburg, Germany — 3Department of Physics, Universität Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
We demonstrate by spin quantum beat spectroscopy that in undoped GaAs/AlGaAs quantum wells even a symmetric spatial wavefunction gives rise to an asymmetric in-plane electron Landé-g-factor if the quantization axis is aligned along the [110] crystal axis. This observation emphasizes the specific symmetry sensing properties of the spin degree of freedom. Choosing the [110] quantization axis lowers the symmetry of the two dimensional system from D2d to C2v symmetry by removal of a mirror plane. This is similar to graded [001] quantum wells, however in the [110] case the spatial part of the wavefunction remains symmetric and only the spin dependent part, i.e., the Dresselhaus and Zeeman contributions, senses the symmetry reduction. This shows that the electron spin is a perfect meter variable to map out the internal –otherwise hidden– symmetries of a given system. The measurements are very well described within 14× 14 band k· p theory and identify the intermixture of different k-dependent Zeeman-split terms as the source for the anisotropy.