Magnetic Field Induced Charged Exciton Studies in a GaAs/Al(0.3)Ga(0.7)As Single Heterojunction

TL;DR

This study investigates the behavior of charged excitons in a GaAs/AlGaAs heterojunction under high magnetic fields, revealing their formation, energy variations, and interaction with fractional quantum Hall states through magnetophotoluminescence.

Contribution

It provides experimental insights into charged exciton states and their energy and intensity variations in high magnetic fields, aligning with theoretical models.

Findings

Charged singlet and triplet excitons observed beyond nu=1 quantum Hall state.

Charged exciton binding energies match theoretical predictions.

MPL transition intensities vary at fractional quantum Hall states due to electron-hole screening effects.

Abstract

The magnetophotoluminescence (MPL) behavior of a GaAs/Al(0.3)Ga(0.7)As single heterojunction has been investigated to 60T. We observed negatively charged singlet and triplet exciton states that are formed at high magnetic fields beyond the nu=1 quantum Hall state. The variation of the charged exciton binding energies are in good agreement with theoretical predictions. The MPL transition intensities for these states showed intensity variations (maxima and minima) at the nu=1/3 and 1/5 fractional quantum Hall (FQH) state as a consequence of a large reduction of electron-hole screening at these filling factors.