Europhys. Lett.
Volume 73, Number 6, March 2006
Page(s) 920 - 926
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
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

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.

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.

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