Dresden 2014 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 24: Topological insulators: mostly interaction with magnetic fields (with MA/TT)

HL 24.7: Vortrag

Montag, 31. März 2014, 17:15–17:30, POT 081

Quantum Oscillations of Photogalvanic Effect and Spin Orbit Interaction Effect in HgTe Quantum Wells — •K.-M. Dantscher1, C. Zoth1, P. Olbrich1, V.V. Belkov2, M.A. Semina2, M.M. Glazov2, L.E. Golub3, D.A. Kozlov3, Z.D. Kvon3, N.N. Mikhailov3, S.A. Dvoretsky3, and S.D. Ganichev11University of Regensburg, Regensburg, Germany — 2Ioffe Institute, St. Petersburg, Russia — 3Institute of Semiconductor Physics, Novosibirsk, Russia

We report on the observation of quantum oscillations in HgTe/HgCdTe quantum well (QW) structures of different widths, which are characterized by an inverted, normal and even Dirac like bandstructure [1,2]. Exciting the QWs by terahertz radiation and sweeping an external magnetic field we observed a resonant photocurrent [3] which shows pronounced oscillations. The photocurrent data are accompanied by measurement of photoconductivity, radiation transmission, as well as, magneto-transport. A comparison of the results shows that the photosignal is enhanced at cyclotron resonance position and is modulated by Shubnikov-De Haas oscillations. Furthermore we present a microscopic model of a magnetic field dependent oscillating current taking into account the oscillations of spin polarization and of conductivity.

[1] Z.D. Kvon et al., JETP Letters 94, 816-819 (2011)
[2] A. Bernevig et al., Science 314, 1757 (2006)
[3] P. Olbrich et al. Phys. Lett B 87, 235439 (2013)

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