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arXiv:cond-mat/0106560 · Physical Review Letters

Restrictions on the Coherence of the Ultrafast Optical Emission from an Electron-Hole-Pair Condensate

Alexandra Olaya-Castro, Ferney J. Rodríguez, Luis Quiroga, C. Tejedor

Published Nov 19, 2001• 28 citations
arXivHTMLPDF

Abstract

We report on the transfer of coherence from a quantum-well electron-hole condensate to the light it emits. As a function of density, the coherence of the electron-hole-pair system evolves from being full for the low-density Bose-Einstein condensate to a chaotic behavior for a high-density BCS-like state. This degree of coherence is transferred to the light emitted in a damped oscillatory way in the ultrafast regime. Additionally, the photon field exhibits squeezing properties during the transfer time. Our results suggest a new type of ultrafast experiments for detecting electron-hole-pair condensation.

DOI
10.1103/physrevlett.87.246403

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We report on the transfer of coherence from a quantum-well electron-hole condensate to the light it emits. As a function of density, the coherence of the electron-hole-pair system evolves from being full for the low-density Bose-Einstein condensate to a chaotic behavior for a high-density BCS-like state. This degree of coherence is transferred to the light emitted in a damped oscillatory way in the ultrafast regime. Additionally, the photon field exhibits squeezing properties during the transfer time. Our results suggest a new type of ultrafast experiments for detecting electron-hole-pair condensation.
The possibility of coherent light emission in systems with a pairing of electrons and holes in a double quantum well spatially separated by a thin barrier (separated electron hole pairs (SEHPs)) is predicted. Bose condensation of excitons formed from SEHPs in GaAs/Al/sub x/Ga/sub (1-x)/As double quantum wells of approximately 10 AA size are possible at relatively high temperatures. Coherent recombination emission due to the transfer of coherence from the Bose-condensed SEHPs to the photon field is expected.>
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