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HL: Fachverband Halbleiterphysik

HL 32: Transport Properties I (mainly Spin Physics and Magnetic Fields)

HL 32.10: Vortrag

Dienstag, 27. März 2012, 12:30–12:45, EW 203

Interplay of spin and orbital magnetogyrotropic photogalvanic effects in InSb-based quantum wells — •Sebastian Stachel¹, Peter Olbrich¹, Christina Zoth¹, Ursula Hagner¹, Thomas Stangl¹, Cynthia Karl¹, Peter Lutz¹, Vasily Bel’kov², Leonid Golub², Steve K. Clowes³, Tim Ashley⁴, Adam M. Gilbertson⁵, and Sergey D. Ganichev¹ — ¹Terahertz Center, University of Regensburg, Regensburg, Germany — ²Ioffe Institute, St. Petersburg, Russia — ³Advanced Technology Institute and SEPNet, University of Surrey, UK — ⁴School of Engineering, University of Warwick, UK — ⁵Blackett Laboratory, Imperial College, UK

Here we report on the observation and detailed study of the magnetic-field induced photocurrents in n-doped InSb/InAlSb quantum wells (QWs). We show that the intraband absorption of terahertz radiation in QWs causes a dc electric current in the presence of an in-plane magnetic field. While at moderate magnetic fields B the photocurrent depends linear on B, at high magnetic fields it becomes nonlinear and inverses its sign. The generation of this current is analyzed in terms of electron gas heating and asymmetric scattering in k-space [1]. We show that due to the narrow gap, strong magnetic proberty and strong spin-orbit coupling this effect is substantially enhanced compared to other III-V materials. It is demonstrated that the strong nonlinear behavior is due to a nonlinear Zeeman spin splitting. [1] V.V. Belkov and S.D. Ganichev, Sem. Sci. Tec. 23, 114003 (2008)