Dresden 2014 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 62: Spintronics I (organized by HL)

TT 62.6: Talk

Wednesday, April 2, 2014, 11:30–11:45, POT 006

Ultrahigh Bandwidth Spin Noise Spectroscopy — •Fabian Berski, Hendrik Kuhn, Jan G. Lonnemann, Jens Hübner, and Michael Oestreich — Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstr. 2, D-30167 Hannover, Germany

We advance all optical spin noise spectroscopy (SNS) in semiconductors to detection bandwidths of several hundred gigahertz by employing a sophisticated scheme of pulse trains from ultrafast laser oscillators as an optical probe [1]. The ultrafast SNS technique avoids the need for optical pumping and enables nearly perturbation free measurements of extremely short spin dephasing times. We apply the technique to highly-n-doped bulk GaAs where magnetic field dependent measurements show unexpected large g-factor fluctuations. Calculations suggest that such large g-factor fluctuations do not necessarily result from extrinsic sample variations but are intrinsically present in every doped semiconductor due to the stochastic nature of the dopant distribution. [1] Berski, F., et al., Phys. Rev. Lett. 111, 186602 (2013).