Excited two-dimensional magnetopolaron states in quantum well of resonant tunnel junction

TL;DR

This study uses tunnel spectroscopy to investigate how high Landau levels in a GaAs quantum well are significantly renormalized due to resonant magnetopolaron formation when specific energy conditions involving LO-phonons and cyclotron energy are met.

Contribution

It demonstrates the observation of resonant magnetopolaron states in a quantum well under magnetic fields, revealing strong electron-phonon interactions at specific energy conditions.

Findings

High Landau levels are drastically renormalized near resonance conditions.

Resonant magnetopolaron formation involves mixing of Landau levels with LO-phonons.

The energy conditions for resonance are when $ abla ext{LO} = m abla ext{C}$, with m=1,2,3.

Abstract

Tunnel spectroscopy is used to probe the electronic structure in GaAs quantum well of resonant tunnel junction over wide range of energies and magnetic fields normal to layers. Spin degenerated high Landau levels ($N=2\div7$) are found to be drastically renormalised near energies when the longitudinal optical-phonon ($\hbar\omega_{LO}$) and cyclotron energy ($\hbar\omega_{C}$) are satisfied condition $\hbar\omega_{LO}=m\hbar\omega_{C}$, where $m=1,2,3$. This renormalisation is attributed to formation of resonant magnetopolarons, i.e. mixing of high index Landau levels by strong interaction of electrons at Landau level states with LO-phonons.