Issue
Europhys. Lett.
Volume 73, Number 6, March 2006
Page(s) 920 - 926
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
DOI http://dx.doi.org/10.1209/epl/i2006-10002-4
Published online 15 February 2006
Europhys. Lett., 73 (6), pp. 920-926 (2006)
DOI: 10.1209/epl/i2006-10002-4

Origin of the inner ring in photoluminescence patterns of quantum well excitons

A. L. Ivanov1, L. E. Smallwood1, A. T. Hammack2, Sen Yang2, L. V. Butov2 and A. C. Gossard3

1  Department of Physics and Astronomy, Cardiff University - Cardiff CF24 3YB, UK
2  Department of Physics, University of California at San Diego La Jolla, CA 92093-0319, USA
3  Materials Department, University of California at Santa Barbara Santa Barbara, CA 93106-5050, USA


received 18 January 2006; accepted in final form 30 January 2006
published online 15 February 2006

Abstract
In order to explain and model the inner ring in photoluminescence (PL) patterns of indirect excitons in GaAs/AlGaAs quantum wells (QWs), we develop a microscopic approach formulated in terms of coupled nonlinear equations for the diffusion, thermalization and optical decay of the particles. The origin of the inner ring is unambiguously identified: it is due to cooling of indirect excitons in their propagation from the excitation spot.

PACS
71.35.-y - Excitons and related phenomena.
73.63.Hs - Electronic transport in nanoscale materials and structures: Quantum wells.
78.67.De - Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures: Quantum wells.

© EDP Sciences 2006