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TT: Fachverband Tiefe Temperaturen
TT 41: Spintronics / Quantum Information: Materials and Methods (jointly with HL)
TT 41.8: Vortrag
Mittwoch, 13. März 2013, 17:00–17:15, H2
Ultrafast Spin Noise Spectroscopy — •Hendrik Kuhn, Fabian Berski, Jan G. Lonnemann, Petrissa Zell, Jens Hübner, and Michael Oestreich — Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstr. 2, D-30167 Hannover
Spin Noise Spectroscopy (SNS) is a powerful experimental technique which explores the full dynamics of stochastically oriented carrier spins close to thermal equilibrium [1]. With the conventional spin noise probing scheme relying on continuous wave (cw) laser probing, the detectable temporal spin dynamic is limited by the electrical bandwidth of the photoreceiver. We advance all optical spin noise spectroscopy in semiconductors to detection bandwidths of several hundred gigahertz by employing an ingenious scheme of pulse trains from ultrafast laser oscillators as an optical probe [2]. As all SNS techniques, ultrafast SNS avoids the need for optical pumping. It enables nearly perturbation free measurements of extremely short spin dephasing times, e.g at high temperatures. We expand our measurements on highly n-doped (n = 8.2 x 1017 cm3) bulk GaAs towards room temperature and demonstrate the feasibility of ultrafast SNS for spin lifetimes down to the order of a few ten picoseconds.
[1] G. M. Müller, M. Oestreich, M. Römer, and J. Hübner Physica 43, 569-587 (2010).
[2] F. Berski et al., arXiv:1207.0081v1 [cond-mat.mes-hall].