Dresden 2017 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 77: Transport in High Magnetic Fields
HL 77.6: Talk
Thursday, March 23, 2017, 16:15–16:30, POT 112
THz radiation induced analog of microwave-induced resistance oscillations in GaAs heterostructures — •Tobias Herrmann1, Ivan A. Dmitriev1,2, Dmitriy A. Kozlov2, Martin Schneider1, Bruno Jentzsch1, Ze Don Kvon4, Peter Olbrich1, Vasily V. Bel'kov3, Andreas Bayer1, Dieter Schuh1, Dominique Bougeard1, Thomas Kuczmik1, Martin Oltscher1, Dieter Weiss1, and Sergey D. Ganichev1 — 1University of Regensburg, Regensburg, Germany — 2Universitätsstr. 31 — 3Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia — 4Novosibirsk State University, Novosibirsk, Russia
We report on the study of terahertz (THz) radiation induced oscillations of magneto-resistivity in AlGaAs/GaAs two dimensional electron systems, the THz analog of microwave induced resistivity oscillations (MIRO). Our experiments answer two most intriguing questions on MIRO, the effect of radiation helicity and the role of the edges yielding crucial information for understanding of the MIRO origin. We exploit the specific advantages of THz laser radiation not present in the MW regime, i.e., the possibility to focus it onto a spot smaller than the sample's size and easy control of the radiation's polarization. The most important features clearly detected on a large variety of samples are (i) a very weak dependence of the oscillations' amplitude on the photon helicity and (ii) the ``bulk'' nature of the effect. Moreover, our study shows that the MIRO oscillations can be excited at THz frequencies even in the samples with low mobility whereas in the MW range ultra-high mobility samples are needed for this type of experiments.