Giant spin-orbit splitting in a HgTe quantum well

TL;DR

This study measures and analyzes large spin-orbit splitting energies in HgTe quantum wells using Shubnikov-de Haas oscillations, confirming theoretical predictions and demonstrating significant spin splitting at room temperature.

Contribution

The paper provides direct experimental determination of large spin-orbit splitting energies in HgTe quantum wells, validated by theoretical calculations and numerical simulations.

Findings

Spin-orbit splitting energies up to 30 meV were observed.

Good agreement between experimental data and 8x8 kp Kane model calculations.

Multiple beating nodes observed in Shubnikov-de Haas oscillations.

Abstract

We have investigated beating patterns in Shubnikov-de Haas oscillations for HgTe/Hg_{0.3}Cd_{0.7}Te(001) quantum wells with electron densities of 2 to 3 X 10^{12} cm^{-2}. Up to 12 beating nodes have been observed at magnetic fields between 0.9 and 6 T. Zero magnetic field spin-orbit splitting energies up to 30 meV have been directly determined from the node positions as well as from the intersection of self-consistently calculated Landau levels. These values, which exceed the thermal broadening of Landau levels, k_B T, at room temperature, are in good agreement with Rashba spin-orbit splitting energies calculated by means of an 8 X 8 kp Kane model. The experimental Shubnikov-de Haas oscillations are also in good agreement with numerical simulations based on this model.