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HL: Fachverband Halbleiterphysik
HL 106: Transport, magnetotransport and quantum Hall physics
HL 106.6: Talk
Friday, March 20, 2015, 11:30–11:45, EW 202
Polarized high power terahertz radiation induced oscillations of magnetoresistivity in GaAs heterostructures — •T. Herrmann1, Z.D. Kvon2, D.A. Kozlov2, V.V. Bel'kov3, B. Jentzsch1, P. Olbrich1, D. Weiss1, and S.D. Ganichev1 — 1University of Regensburg, Regensburg, Germany — 2Institute of Semiconductor Physics, Novosibirsk, Russia — 3Ioffe Institute, St. Petersburg, Russia
We report on the study of terahertz (THz) high power laser radiation induced magnetoresistivity oscillations (TIRO) in a high density two-dimensional electron gas in GaAs quantum wells. TIRO were observed at He temperature in Corbino disc samples applying a magnetic field and nanosecond pulses of intense THz radiation of pulsed molecular laser operating in a frequency range from 0.6 to 2 THz [1]. The positions of oscillation maxima in magnetic field correspond to that of high harmonics of the cyclotron resonance (CR). Up to 9 harmonics are detected, having comparable amplitudes and yielding signals larger than that of the CR itself. Applying right- and left-handed polarized radiation we demonstrate that, while for a fixed magnetic field direction the CR is excited only for one light helicity the TIRO are insensitive to the radiation polarization state. Investigating TIRO for different power levels varying in the range from Watts to tens of kW we also show that the amplitude of the oscillations saturates with raising power.
[1] S.D. Ganichev and W. Prettl, Intense Terahertz Excitation of Semiconductors, Oxford University Press (2006)