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

作者：Galeeva Alexandra V; Artamkin Alexey I; Kazakov Alexey S; Danilov Sergey N; Dvoretskiy Sergey A; Mikhailov Nikolay N; Ryabova Ludmila I; Khokhlov Dmitry R

来源：Beilstein Journal of Nanotechnology, 2018, 9: 1035-1039.

DOI：10.3762/bjnano.9.96

<jats:p>Terahertz photoconductivity in heterostructures based on n-type Hg<jats:sub>1−</jats:sub>
<jats:italic>
<jats:sub>x</jats:sub>
</jats:italic>Cd<jats:italic>
<jats:sub>x</jats:sub>
</jats:italic>Te epitaxial films both in the topological phase (<jats:italic>x</jats:italic> &lt; 0.16, inverted band structure, zero band gap) and the trivial state (<jats:italic>x</jats:italic> &gt; 0.16, normal band structure) has been studied. We show that both the positive photoresponse in films with <jats:italic>x</jats:italic> &lt; 0.16 and the negative photoconductivity in samples with <jats:italic>x</jats:italic> &gt; 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.</jats:p>

• 出版日期2018-3-29