Localization-Delocalization Transition of Indirect Excitons in Lateral Electrostatic Lattices

TL;DR

This paper investigates how indirect excitons in quantum wells transition from localized to delocalized states when subjected to lateral electrostatic lattices, revealing the role of exciton interactions and lattice amplitude.

Contribution

It demonstrates the localization-delocalization transition of excitons in electrostatic lattices and links the transition to exciton interactions and external potential parameters.

Findings

Transition occurs with decreasing lattice amplitude or increasing exciton density.

Interaction energy at transition is comparable to lattice amplitude.

Model suggests percolation driven by exciton interactions.

Abstract

We study transport of indirect excitons in GaAs/AlGaAs coupled quantum wells in linear lattices created by laterally modulated gate voltage. The localization-delocalization transition (LDT) for transport across the lattice was observed with reducing lattice amplitude or increasing exciton density. The exciton interaction energy at the transition is close to the lattice amplitude. These results are consistent with the model, which attributes the LDT to the interaction-induced percolation of the exciton gas through the external potential. We also discuss applications of the lattice potentials for estimating the strength of disorder and exciton interaction.