耦合量子阱中间接激子的受激散射：激子简并玻色气体的特征

Stimulated scattering of indirect excitons in coupled quantum wells: signature of a degenerate Bose-gas of excitons.

作者信息

Butov L V, Ivanov A L, Imamoglu A, Littlewood P B, Shashkin A A, Dolgopolov V T, Campman K L, Gossard A C

机构信息

Institute of Solid State Physics, Russian Academy of Sciences, 142432 Chernogolovka, Russia.

出版信息

Phys Rev Lett. 2001 Jun 11;86(24):5608-11. doi: 10.1103/PhysRevLett.86.5608.

DOI:10.1103/PhysRevLett.86.5608

PMID:11415313

Abstract

We observe and analyze strongly nonlinear photoluminescence kinetics of indirect excitons in GaAs/AlGaAs coupled quantum wells at low bath temperatures, > or = 50 mK. The long recombination lifetime of indirect excitons promotes accumulation of these Bose particles in the lowest energy states and allows the photoexcited excitons to cool down to temperatures where the dilute 2D gas of indirect excitons becomes statistically degenerate. Our main result--a strong enhancement of the exciton scattering rate to the low-energy states with increasing concentration of the indirect excitons--reveals bosonic stimulation of exciton scattering, which is a signature of a degenerate Bose-gas of excitons.

摘要

我们观测并分析了在低温（≥50 mK）下GaAs/AlGaAs耦合量子阱中间接激子的强非线性光致发光动力学。间接激子的长复合寿命促使这些玻色子粒子在最低能量态积累，并使光激发激子冷却至间接激子的二维稀薄气体发生统计简并的温度。我们的主要结果——随着间接激子浓度增加，激子向低能态的散射速率显著增强——揭示了激子散射的玻色子刺激效应，这是激子简并玻色气体的一个特征。