Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 13: Spin controlled transport I

HL 13.4: Talk

Tuesday, March 28, 2006, 11:45–12:00, BEY 118

Optical investigation of spin polarization in semiconductor heterostructures — •Ulrich Niedermeier, Klaus Wagenhuber, Christian Gerl, and Werner Wegscheider — Institut für Experimentelle und Angewandte Physik, Universität Regensburg, 93040 Regensburg

Creating spin polarization in low-dimensional semiconductor systems is essential for the realization of new concepts in the field of spintronics. It has been shown that in systems with lifted spin degeneracy due to spin-orbit interaction a new class of spin-related effects can be observed [1]. While the spin-galvanic effect is referred to as a current induced by spin orientation we are investigating the reversed spin-galvanic effect, i.e. a spin orientation induced by a current. Recently, it has been demonstrated by means of optical interband spectroscopy that passing an electric current in lateral geometry through a two-dimensional hole system leads to an orientation of spins [2]. In order to reproduce this effect photoluminescence measurements of modulation doped p-type AlGaAs/GaAs heterojunctions under current flow are performed. The analysis of the circular polarization of the photoluminescence signal should give a low-limit estimate of the spin polarization achieved.

[1] S. D. Ganichev, W. Prettl, J. Phys.: Condens. Matter (Topical Review) 15, R935 (2003).

[2] A. Yu. Silov et al., Appl. Phys. Lett. 85, 5929-5931 (2004).