Inhibited Recombination of Charged Magnetoexcitons

TL;DR

This paper demonstrates that high magnetic fields significantly prolong the decay time of charged excitons in GaAs quantum wells by spatially confining them, reducing recombination rates due to decreased phase coherence.

Contribution

It introduces the concept of magnetically-adjustable quantum dots that inhibit recombination of charged excitons through magnetic confinement.

Findings

Decay time increases by an order of magnitude at high magnetic fields

Charged excitons are spatially confined by cyclotron orbits and quantum wells

Recombination is inhibited due to reduced phase coherence volume

Abstract

Time-resolved photoluminescence measurements show that the decay time for charged excitons in a GaAs two-dimensional electron gas increases by an order of magnitude at high magnetic fields. Unlike neutral excitons, the charged exciton center-of-mass is spatially confined in a ``magnetically-adjustable quantum dot'' by the cyclotron orbit and the quantum well. The inhibited recombination is explained by a reduced phase coherence volume of the magnetically-confined charged excitons.