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SYSC: Symposium Spin Coherence in Solids

SYSC 1: Spin Coherence in Solids

SYSC 1.2: Hauptvortrag

Mittwoch, 25. März 2009, 10:00–10:30, BAR SCHÖ

Dyakonov-Perel' Spin-Dynamics in GaAs Quantum Wells — •Richard Harley — School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK

The development of semiconductor spintronic devices calls for long electron spin memory combined with an ability to control and tune the spin with external gate voltage at room temperature. Two-dimensional III-V structures appear to have the potential for room temperature electron spin memory in the nanosecond range, comparable to silicon, but tuneable down to tens of picoseconds. This is because the Dyakonov-Perel' (DP) spin relaxation mechanism, which relies on the spin-orbit splitting of the conduction band as the driving force for spin reorientation, is usually dominant in such systems and there is considerable potential for manipulation and tuning the spin-orbit splitting in 2D systems. This talk will describe recent ultra-fast optical experiments which have been aimed at understanding the DP mechanism in depth in GaAs quantum wells. These include investigations of the transition from the weak to the strong scattering regimes in 2DEGs, of the suppression of the DP mechanism in (110)-grown quantum wells, and of tuning the DP mechanism by means of in-built asymmetry and applied electric field.