Regensburg 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 34: Poster I: III-V Semiconductors
HL 34.10: Poster
Dienstag, 23. März 2010, 18:30–20:30, Poster D2
Spin dynamics in high-mobility (110) GaAs based quantum wells — •Roland Völkl1, Tobias Korn1, Michael Griesbeck1, Andreas Maurer1, Dieter Schuh1, Werner Wegscheider2, Sergey Tarasenko3, Eugenius Ivchenko3, and Christian Schüller1 — 1Universität Regensburg, Germany — 2ETH Zurich, Switzerland — 3A. F. Ioffe Physical-Technical Institute, Russia
[110]-grown quantum wells have been studied intensely in recent years, due to the observation of long spin life times, which are caused by the suppression of the Dyakonov-Perel mechanism. Here, we present the results of electron/spin diffusion experiments in (110) grown GaAs-based quantum wells. The Hanle-MOKE method is used to determine the spin lifetime and for mapping the motion of spin-polarized electrons. Spins are continuously injected with a circularly polarized CW laser and the net spin polarization perpendicular to the sample plane is measured by detecting the Kerr rotation of a linearly polarized laser. Both laser beams are focused through an optical microscope onto the sample. Measurements of the spin lifetime show two regions with different increase of the dephasing rate with respect to the excitation intensity due to a saturation of the spin polarization. The pump beam spot can be moved on the sample with a motorized mirror. Hereby, a mapping of the spin diffusion is possible and the spin polarized electrons can be followed up to a distance of about 50 microns from the excitation spot. The effect of the saturation of the spin polarization affects also the diffusion behavior at high intensities.