Anisotropic conductivity and weak localization in HgTe quantum well with normal energy spectrum

TL;DR

This study investigates interference magnetoconductivity in narrow HgTe quantum wells with a normal spectrum, revealing how phase relaxation time varies with conductivity and temperature, and contrasting it with inverted spectrum wells.

Contribution

It provides the first detailed analysis of anisotropic interference magnetoconductivity in narrow HgTe quantum wells with a normal spectrum, highlighting differences from inverted spectrum wells.

Findings

Phase relaxation time increases with conductivity and decreases with temperature following 1/T law.

Behavior differs from wide HgTe wells with inverted spectrum, where au_ ext{phi} is nearly independent of conductivity.

Electron wave function structure may explain the discrepancy between normal and inverted spectrum wells.

Abstract

The results of experimental study of interference induced magnetoconductivity in narrow quantum well HgTe with the normal energy spectrum are presented. Analysis is performed with taking into account the conductivity anisotropy. It is shown that the fitting parameter \tau_\phi corresponding to the phase relaxation time increases in magnitude with the increasing conductivity (\sigma) and decreasing temperature following the 1/T law. Such a behavior is analogous to that observed in usual two-dimensional systems with simple energy spectrum and corresponds to the inelasticity of electron-electron interaction as the main mechanism of the phase relaxation. However, it drastically differs from that observed in the wide HgTe quantum wells with the inverted spectrum, in which \tau_\phi being obtained by the same way is practically independent of \sigma. It is presumed that a different structure of the electron multicomponent wave function for the inverted and normal quantum wells could be reason for such a discrepancy.