Bose-Einstein Condensation of Excitons in a Semiconductor(Current Topics)

Abstract

An electron and a hole in semiconductors combine with each other by Coulomb attraction to form an exciton. This hydrogen-like quasiparticle obeys Bose statistics and it has been predicted that the system shows Bose-Einstein condensation by keeping an exciton gas low temperature and high density under the quasi-equilibrium condition. We have observed the transition to a Bose-Einstein condensate of an quasi-equilibrium, photo-excited exciton system in cuprous oxide. This is a big step towards the resolution of the long-term problem, and this will be a milestone for future fascinating studies on the matter phases in quantum manybody system of electrons and holes.