Many-particle effects in optical transitions from zero-mode Landau levels in HgTe quantum wells

TL;DR

This study investigates how electron-electron interactions influence optical transitions from zero-mode Landau levels in HgTe quantum wells, revealing their significant role alongside structural asymmetries through magnetospectroscopy.

Contribution

It demonstrates the impact of electron-electron interactions on optical transitions in HgTe quantum wells, a factor previously underappreciated in this context.

Findings

Transition energies depend on electron concentration.

Electron-electron interactions significantly affect optical transitions.

Persistent photoconductivity modulates transition energies.

Abstract

We report on the far-infrared magnetospectroscopy of HgTe quantum wells with inverted band ordering at different electron concentrations. We particularly focus on optical transitions from zero-mode Landau levels, which split from the edges of electron-like and hole-like bands. We observe a pronounced dependence of the transition energies on the electron concentration varied by persistent photoconductivity effect. This is striking evidence that in addition to the already well-documented crystalline and interface asymmetries, electron-electron interactions also have a significant impact on the usual behavior of the optical transitions from zero mode Landau levels.