Theory of Luminescence Spectra of High-Density Electron-Hole Systems: Crossover from Excitonic Bose-Einstein Condenstation to Electron-Hole BCS State

Abstract

We present a unified theory of luminescence spectra for highly excited semiconductors, which is applicable both to the electron-hole BCS state and to the exciton Bose-Einstein condensate. The crossover behavior between electron-hole BCS state and exciton Bose-Einstein condensate clearly manifests itself in the calculated luminescence spectra. The analysis is based on the Bethe-Salpeter equation combined with the generalized random-phase-approximation, which enables us to consider the multiple Coulomb scattering and the quantum fluctuation associated with the center-of-mass motion of electron-hole pairs. In the crossover regime, the calculated spectra are essentially different from results obtained by the BCS-like mean-field theory and the interacting Boson model. In particular, it is found that the broad spectrum, arising from the recombination of electron-hole BCS state, splits into the P- and P_2-luminescence bands with decreasing the particle density. The dependence of these bands on the carrier density is in good agreement with experiments for highly excited semiconductors.

9 pages, 4 figures, To appear in Solid State Communications

Cited by in corpus (4)

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• Restrictions on the coherence of the ultrafast optical emission from an electron-hole pairs condensate
• Condensation of electron-hole pairs in a degenerate semiconductor at room temperature
• Many-body theory of pump-probe spectra for highly excited semiconductors