Aniotropy of in-plane g-factor of electrons in HgTe quantum wells

TL;DR

This study investigates the anisotropy of the in-plane g-factor of electrons in HgTe quantum wells through experimental Shubnikov-de Haas oscillations, revealing strong anisotropy in inverted spectrum wells and slight in-plane anisotropy in normal spectrum wells.

Contribution

It provides a comprehensive analysis of g-factor anisotropy in HgTe quantum wells, incorporating interface inversion asymmetry in theoretical modeling to match experimental results.

Findings

Strong in-plane g-factor anisotropy in inverted spectrum QWs.

Weak in-plane anisotropy in normal spectrum QWs.

Quantitative agreement between experiment and four-band kP model with interface asymmetry.

Abstract

The results of experimental studies of the Shubnikov-de Haas (SdH) efect in the (013)-HgTe/Hg$_{1-x}$Cd$_x$Te quantum wells (QWs) of electron type of conductivity both with normal and inverted energy spectrum are reported. Comprehensive analysis of the SdH oscillations measured for the different orientations of magnetic field relative to the quantum well plane and crystallographic exes allows us to investigate the anisotropy of the Zeeman effect. For the QWs with inverted spectrum, it has been shown that the ratio of the spin splitting to the orbital one is strongly dependent not only on the orientation of the magnetic field relative to the QW plane but also on the orientation of the in-plane magnetic field component relative to crystallographic axes laying in the QW plane that implies the strong anisotropy of in-plane g-factor. In the QW with normal spectrum, this ratio strongly depends on the angle between the magnetic field and the normal to the QW plane and reveals a very slight anisotropy in the QW plane. To interpret the data, the Landau levels in the tilted magnetic field are calculated within the framework of four-band \emph{kP} model. It is shown that the experimental results can be quantitatively described only with taking into account the interface inversion asymmetry.