= Exciton condensation
<Exciton condensation> is collective <quantum coherence> of <electron-hole pairs> or excitonic <degrees of freedom>. A finite exciton population alone does not establish it; the central issue is macroscopic phase coherence or the corresponding ordered state.
The physical setting matters. Long-lived excitons in a semiconductor, electron-hole bilayers and driven exciton-polariton systems have different <conservation laws>, <decay channels> and interactions. A spectral feature or an increase in emitted intensity therefore needs supporting coherence and dynamical evidence before being interpreted as condensation.<Bose-Einstein Condensation of Excitons in Cu2O: Progress Over Thirty Years by David Snoke and G. M. Kavoulakis>[review of experimental criteria and exciton systems]{ref}
Back to article page
