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HL: Fachverband Halbleiterphysik
HL 71: Quantum Dots and Wires: Optical Properties
HL 71.8: Talk
Thursday, March 10, 2016, 11:45–12:00, H15
Spin-lattice relaxation time of InGaAs quantum dots — •Daniel A. Lübke1, Evgeny A. Zhukov1, Alex Greilich1, Erik Kirstein1, Fabian Heisterkamp1, Tomasz Kazimierczuk1, Vladimir L. Korenev1,2, Dirk Reuter3, Andreas D. Wieck3, Dmitri R. Yakovlev1,2, and Manfred Bayer1,2 — 1Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany — 2Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia — 3Angewandte Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum, Germany
We demonstrate measurements of the spin relaxation time (T1) of resident electrons and holes in ensembles of InGaAs quantum dots. These measurements are done using a new method exploiting the spin inertia, based on the pump-probe type of measurements. Here the helicity of the pump laser is switched between both circular polarizations with variable frequency, at fixed pump-probe delay. At low frequencies of modulation, the created spin polarization is able to reach its steady state value, the maximal signal. If the pump helicity changes faster, so that the spin polarization cannot reach its steady state, it results in a decreased signal. We use this technique to evaluate the T1 time in dependence on the longitudinal magnetic field in the range of ± 300 mT.