Circular photogalvanic effect in HgTe/CdHgTe quantum well structures

B. Wittmann, S. N. Danilov, V. V. Bel'kov, S. A. Tarasenko, E. G. Novik, H. Buhmann, C. Brüne, L. W. Molenkamp, Z. D. Kvon, N. N. Mikhailov, S. A. Dvoretsky, N. Q. Vinh, A. F. G. van der Meer, B. Murdin, S. D. Ganichev

Published 2010-02-12Version 1

We describe the observation of the circular and linear photogalvanic effects in HgTe/CdHgTe quantum wells. The interband absorption of mid-infrared radiation as well as the intrasubband absorption of terahertz (THz) radiation in the QWs structures is shown to cause a dc electric current due to these effects. The photocurrent magnitude and direction varies with the radiation polarization state and crystallographic orientation of the substrate in a simple way that can be understood from a phenomenological theory. The observed dependences of the photocurrent on the radiation wavelength and temperature are discussed.