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SYSS: Symposium Spins in Semiconductors
SYSS 1: Spins in Semiconductors
SYSS 1.2: Hauptvortrag
Montag, 26. März 2007, 10:00–10:20, H1
Spin noise spectroscopy and spin dynamics in semiconductors — •Michael Oestreich1, Michael Römer1, Stefanie Döhrmann1, Stefan Oertel1, Daniel Hägele1,2, and Jens Hübner1 — 1Leibniz Universität Hannover, Institute for Solid State Physics, Appelstraße 2, D-30167 Hannover, Germany — 2now at: Ruhr-Universität Bochum
In the first part of our talk we will introduce spin noise spectroscopy as a nearly perturbation free method to study the electron Landé g-factor and the spin dynamics in semiconductors. Spin noise spectroscopy is an astonishing sensitive technique enabling low temperature measurements on few carrier spins. The technique avoids unintentional heating of the lattice and of free or bound carriers. Spin noise spectroscopy also avoids the creation of holes and thereby suppresses spin relaxation induced by the measurement itself.
In the second part of our talk we study the electron spin dynamics in GaAs by spin noise spectroscopy and time-resolved photoluminescence. As expected, the two techniques exhibit distinct differences in the measured low temperature electron g-factor and spin relaxation times. Very elaborate long-term time-resolved measurements yield information about the dynamics of nuclear spin polarization by optical pumping. The experiments clearly show different time scales for the dynamic nuclear polarization and in combination with temperature dependent measurements enable the determination of the pure free electron Landé g-factor with unprecedented accuracy.