This article is cited in 8 papers

CONDENSED MATTER

Terahertz electron transport in a two-dimensional topological insulator in a HgTe quantum well

Z. D. Kvon^ab, K. M. Dantscher^c, C. Zoth^c, D. A. Kozlov^ab, N. N. Mikhailov^ab, S. A. Dvoretskii^a, S. D. Ganichev<sup>c

a</sup> Rzhanov Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences, Novosibirsk
^b Novosibirsk State University
^c Terahertz Center, University of Regensburg

Abstract: The terahertz response of a two-dimensional topological insulator in a HgTe quantum well to radiation with wavelengths of $118$ and $184$ $\mu$m is investigated. It is found that the photoconductivity is rather high (up to a few percent of dark conductivity) and is manifested in both the local and nonlocal responses of the system. This fact proves that the observed photoconductivity is caused by changes in the transport via edge current-carrying states. The sign and nonresonant character of the photoconductivity indicate that it is caused by the heating of electrons in the system. The analysis of experimental results makes it possible to suggest that this heating originates from the Drude absorption of terahertz radiation by metallic “droplets” appearing owing to fluctuations in the impurity potential and the gap and located in direct proximity to edge states.

Received: 04.02.2014

DOI: 10.7868/S0370274X14050117

 English version: Journal of Experimental and Theoretical Physics Letters, 2014, 99:5, 290–294

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