Quantized Vortices and Four-Component Superfluidity of Semiconductor Excitons

TL;DR

This paper reports the observation of quantized vortices and macroscopic coherence in a four-component superfluid of semiconductor excitons confined in a quantum well at very low temperatures, revealing complex quantum fluid behavior.

Contribution

It demonstrates the formation of a four-component superfluid involving bright and dark excitons, with quantum signatures observed in photoluminescence at ultra-low temperatures.

Findings

Detection of macroscopic spatial coherence below 1 Kelvin

Observation of quantized vortices in exciton superfluid

Superfluid composed of bright and dark excitons in a dilute regime

Abstract

We study spatially indirect excitons of GaAs quantum wells, confined in a 10 microns electrostatic trap. Below a critical temperature of about 1 Kelvin, we detect macroscopic spatial coherence and quantised vortices in the weak photoluminescence emitted from the trap. These quantum signatures are restricted to a narrow range of density, in a dilute regime. They manifest the formation of a four-component superfluid, made by a low population of optically bright excitons coherently coupled to a dominant fraction of optically dark excitons.