Tunnelling Studies of Two-Dimensional States in Semiconductors with Inverted Band Structure: Spin-orbit Splitting, Resonant Broadening

TL;DR

This study investigates the energy spectrum and spin-orbit splitting of two-dimensional states in inverted band structure semiconductors using tunnelling spectroscopy, revealing how quantum well properties influence these states.

Contribution

It provides a detailed analysis of 2D state spectra, spin-orbit effects, and broadening phenomena in inverted band semiconductors using tunnelling methods and Kane model calculations.

Findings

Spin-orbit splitting is observed due to surface quantum well asymmetry.

Resonant broadening occurs when 2D states align with heavy hole valence band.

Theoretical results align well with experimental tunnelling data.

Abstract

The results of tunnelling studies of the energy spectrum of two-dimensional (2D) states in a surface quantum well in a semiconductor with inverted band structure are presented. The energy dependence of quasimomentum of the 2D states over a wide energy range is obtained from the analysis of tunnelling conductivity oscillations in a quantizing magnetic field. The spin-orbit splitting of the energy spectrum of 2D states, due to inversion asymmetry of the surface quantum well, and the broadening of 2D states at the energies, when they are in resonance with the heavy hole valence band, are investigated in structures with different strength of the surface quantum well. A quantitative analysis is carried out within the framework of the Kane model of the energy spectrum. The theoretical results are in good agreement with the tunnelling spectroscopy data.