Indirect excitons in (111) GaAs double quantum wells. (August 2017)

• Record Type: Journal Article
• Authors: Hubert, C.; Biermann, K.; Hernández-Mínguez, A.; Santos, P.V.
• Is Part Of: Superlattices and microstructures. Volume 108(2017)
• Page Start: 51
• Page End: 56
• Publication Date: 2017-08
• Subjects: Indirect exctions -- Drift-diffusion -- Dipolar interactions -- (111) GaAs; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2017.01.023
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: We study the dynamics of indirect (or dipolar) excitons (interwell IXs) in GaAs (111) double quantum wells (DQWs) subjected to a transverse electric field. In comparison with single (111) QWs, these DQWs can store, for a comparable applied fields and optical excitation density, a density of interwell IXs much larger than in SQWs, thus leading to stronger interwell IX- IX repulsive interactions. We show by means of spatially-resolved optical spectroscopy that interwell IXs in (111) DWQs can be transported over distances exceeding 60 μm. From the spectral dependence of the interwell IX spatial distribution profiles, we show that the long transport distances are due to drift forces arising from the strong interwell IX- IX interactions. Highlights: Piezoelectric fields across (111) GaAs double quantum wells trap high indirect exciton densities. Indirect excitons in (111) GaAs diffuse over larger length scales than in a single quantum well. The indirect excitons in (111) GaAs reach much higher densities than in single quantum well systems.