Excitation Energy Dependence of the Exciton Inner Ring

TL;DR

This paper investigates how the excitation energy affects the exciton inner ring pattern, revealing that lower excitation energies reduce contrast and help achieve colder, denser exciton gases through improved transport and cooling.

Contribution

It provides new insights into how excitation energy influences exciton transport and cooling, enabling better control of exciton gases in experiments.

Findings

Lower excitation energy decreases inner ring contrast.

Resonant excitation suppresses heating of indirect excitons.

Exciton transport and cooling explain the energy dependence.

Abstract

We report on the excitation energy dependence of the inner ring in the exciton emission pattern. The contrast of the inner ring is found to decrease with lowering excitation energy. Excitation by light tuned to the direct exciton resonance is found to effectively suppress excitation-induced heating of indirect excitons and facilitate the realization of a cold and dense exciton gas. The excitation energy dependence of the inner ring is explained in terms of exciton transport and cooling.