Publication Date:
2017-04-26
Description:
Author(s): P. Faltermeier, G. V. Budkin, J. Unverzagt, S. Hubmann, A. Pfaller, V. V. Bel'kov, L. E. Golub, E. L. Ivchenko, Z. Adamus, G. Karczewski, T. Wojtowicz, V. V. Popov, D. V. Fateev, D. A. Kozlov, D. Weiss, and S. D. Ganichev This paper reports on the observation of the magnetic quantum ratchet effect in (Cd,Mn)Te- and CdTe-based quantum well structures with an asymmetric lateral dual grating gate superlattice subjected to an external magnetic field ( B ), applied normal to the quantum well plane. An electric current excited by terahertz laser radiation shows 1/ B -periodic oscillations with amplitude much larger than the photocurrent at zero magnetic field. It is shown that the photocurrent generation is due to the combined action of a spatially periodic lateral potential and the spatially modulated radiation due to the near-field effects of light diffraction. The magnitude and direction of the photocurrent are determined by the degree of the lateral asymmetry controlled by the variation of voltages applied to the individual gates. The observed magneto-oscillations with enhanced photocurrent amplitude result from Landau quantization. For (Cd,Mn)Te-based structures at low temperatures, a beating-like pattern of the oscillations is observed, caused by the interplay of Zeeman and Landau splitting. A theoretical analysis, considering the magnetic quantum ratchet effect in the framework of a semiclassical approach, describes quite well the experimental results. [Phys. Rev. B 95, 155442] Published Mon Apr 24, 2017
Keywords:
Surface physics, nanoscale physics, low-dimensional systems
Print ISSN:
1098-0121
Electronic ISSN:
1095-3795
Topics:
Physics
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