Non-equilibrium electron transport induced by terahertz radiation in the topological and trivial phases of Hg1−xCdxTe

Beilstein Journal of Nanotechnology

Ludmila I. Ryabova¹  Sergey N. Danilov²  Alexandra V. Galeeva³  Dmitry R. Khokhlov³  Alexey S. Kazakov³  Alexey I. Artamkin³  Sergey A. Dvoretskiy⁴  Nikolay N. Mikhailov⁴ 

[1]Chemistry Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1 bld.3, 119991 Moscow, Russia

[2]Faculty of Physics, University of Regensburg, Universitaetstr. 31, D-93053 Regensburg, Germany

[3]Physics Department, M.V. Lomonosov Moscow State University, Leninskie Gory 1 bld.2, 119991 Moscow, Russia

[4]Rzhanov Institute of Semiconductor Physics, pr. Lavrentieva 13, 630090 Novosibirsk, Russia

关键词: terahertz radiation;    topological insulator;    photoconductivity;   

DOI  :  10.3762/bjnano.9.96

来源: DOAJ

【 摘 要 】

Terahertz photoconductivity in heterostructures based on n-type Hg1−xCdxTe epitaxial films both in the topological phase (x < 0.16, inverted band structure, zero band gap) and the trivial state (x > 0.16, normal band structure) has been studied. We show that both the positive photoresponse in films with x < 0.16 and the negative photoconductivity in samples with x > 0.16 have no low-energy threshold. The observed non-threshold positive photoconductivity is discussed in terms of a qualitative model that takes into account a 3D potential well and 2D topological Dirac states coexisting in a smooth topological heterojunction.

【 授权许可】

Unknown