Evidence for Bose-Einstein Statistics in an Exciton Gas

Abstract

A free-exciton gas is studied as a function of generated particle density in ${\mathrm{Cu}}_{2}$O at 1.5 K. A line-shape analysis of the subsequent recombination shows a gradual evolution, from a classical regime at low density, to a highly quantum-statistical one with chemical potential $\ensuremath{\mu}\ensuremath{\simeq}0$.