Coulomb Driven New Bound States at the Integer Quantum Hall States in GaAs/Al(0.3)Ga(0.7)As Single Heterojunctions

TL;DR

This study reveals Coulomb-driven bound states in GaAs/AlGaAs heterojunctions under high magnetic fields, showing unique hole localization effects at specific Landau filling factors.

Contribution

It uncovers new Coulomb-driven bound states in heterojunctions, highlighting the role of valence hole dynamics in strong magnetic fields, a novel observation in this material system.

Findings

Bound states observed at low magnetic fields (nu > 2).

Strong Mott-type localizations at nu < 1 and 1 < nu < 2.

Unique hole localization due to open valence band structure.

Abstract

Coulomb driven, magneto-optically induced electron and hole bound states from a series of heavily doped GaAs/Al(0.3)Ga(0.7)As single heterojunctions (SHJ) are revealed in high magnetic fields. At low magnetic fields (nu > 2), the photoluminescence spectra display Shubnikov de-Haas type oscillations associated with the empty second subband transition. In the regime of the Landau filling factor nu < 1 and 1 < nu <2, we found strong bound states due to Mott type localizations. Since a SHJ has an open valence band structure, these bound states are a unique property of the dynamic movement of the valence holes in strong magnetic fields.