Peculiarities of the electronic transport in topological materials of Bi2Se3 and MoxW1-xTe2 (x = 0; 0.5; 1)

V V Chistyakov,A N Domozhirova,J C A Huang,V V Marchenkov,S V Naumov

doi:10.1088/1742-6596/1410/1/012199

Abstract

The electrical resistivity of thin films of a topological insulator of Bi2Se3 with a thickness of 10 nm to 75 nm, single crystal of Bi2Se3 with thickness of 0.65 mm and single crystals of topological Weyl semimetals MoxW1-xTe2 (x = 0; 0.5; 1) in the temperature range from 4.2 to 300 K was measured. A size effect in the electrical conductivity of Bi2Se3 films was observed, i.e. linear dependence of the conductivity of the film on its reciprocal thickness. It is suggested the existence of two different conduction channels in the Mo0.5W0.5Te2 compound.

Highlights

In recent years new quantum materials with a topologically nontrivial band structure resulting from strong spin-orbit interaction have been predicted theoretically and discovered experimentally
A size effect in the electrical conductivity of Bi2Se3 films was observed, i.e. linear dependence of the conductivity of the film on its reciprocal thickness. It is suggested the existence of two different conduction channels in the Mo0.5W0.5Te2 compound
The rigid coupling between the directions of the pulse and the electron spin leads to the appearance of spin polarization of charge carriers and the possibility of spin-polarized current flowing near the surface of the topological insulators (TI) with virtually no losses [1]

Summary

Introduction

In recent years new quantum materials with a topologically nontrivial band structure resulting from strong spin-orbit interaction have been predicted theoretically and discovered experimentally. First of all, these are topological insulators (TI) [1]. In these compounds there is an energy gap in the bulk of the material, characteristic of an insulator, and protected gapless conducting states on its surface Such materials include Bi2Se3, Bi2Te3, Sb2Te3 and etc. The quasiparticles in the bulk of Weyl semimetals are “massless” Weyl fermions [2], with a "zero" effective mass, which are protected topologically This means that such quasiparticles can be controlled much faster than conventional charge carriers, and the probability of their scattering is sufficiently small. It is known [7,8,9] that the WTe2 compound usually exhibits semimetallic properties and has a “metallic” type of temperature dependence of the electroresistivity ρ(T), whereas the MoTe2 has a “semiconductor” dependence ρ(T)

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