Origin of the inner ring in photoluminescence patterns of quantum well excitonsA. 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.
© EDP Sciences 2006