# Evidence for a Bose-Einstein condensate of excitons

Abstract : We report compelling evidence for a gray'' condensate of dipolar excitons, electrically polarised in a 25 nm wide GaAs quantum well. The condensate is composed by a macroscopic population of dark excitons coherently coupled to a lower population of bright excitons. To create the exciton condensate we use an all-optical approach in order to produce microscopic traps which confine a dense exciton gas (similar to 10(10) cm(-2)) that yet exhibits an anomalously weak photoemission at sub-kelvin temperatures. This is the first fingerprint for the gray'' condensate. It is then confirmed by the macroscopic spatial coherence and the linear polarization of the weak excitonic photoluminescence emitted from the trap, as theoretically predicted.
Document type :
Journal articles

https://hal.archives-ouvertes.fr/hal-01229150
Contributor : Gestionnaire Hal-Upmc <>
Submitted on : Monday, November 16, 2015 - 1:39:32 PM
Last modification on : Thursday, July 1, 2021 - 5:32:08 PM

### Citation

Mathieu Alloing, Mussie Beian, Maciej Lewenstein, David Fuster, Yolanda Gonzalez, et al.. Evidence for a Bose-Einstein condensate of excitons. EPL - Europhysics Letters, European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing, 2014, 107 (1), pp.10012 ⟨10.1209/0295-5075/107/10012⟩. ⟨hal-01229150⟩

Record views