Abstract
Bose-Einstein condensation (BEC) is a thermodynamic phase transition of an interacting Bose gas. Its key signatures are remarkable quantum effects like superfluidity and a phonon-like Bogoliubov excitation spectrum, which have been verified for atomic BECs. In the solid state, BEC of exciton-polaritons has been reported. Polaritons are strongly coupled light-matter quasiparticles in semiconductor microcavities and composite bosons. However, they are subject to dephasing and decay and need external pumping to reach a steady state. Accordingly the polariton BEC is a nonequilibrium process of a degenerate polariton gas in self-equilibrium, but out of equilibrium with the baths it is coupled to and therefore deviates from the thermodynamic phase transition seen in atomic BECs. Here we show that key signatures of BEC can even be observed without fulfilling the self-equilibrium condition in a highly photonic quantum degenerate nonequilibrium system.
Original language | English |
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Pages (from-to) | 1804-1809 |
Number of pages | 6 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 108 |
Issue number | 5 |
DOIs | |
Publication status | Published - 1 Feb 2011 |
Keywords
- photon statistics
- quantum optics
- semiconductor photon sources
- BOSE-EINSTEIN CONDENSATION
- SEMICONDUCTOR MICROCAVITY
- QUANTIZED VORTICES
- EXCITON POLARITONS
- DYNAMICS