On the Bose–Einstein Condensate of Excitons in Crystals with Defects

The possibility of formation of a Bose–Einstein condensate (BEC) of excitons in a model nonideal lattice of a molecular crystal is considered. The spectrum of corresponding exciton excitations is analyzed. The dependence of the chemical potential on the concentration of structural defects is numerically simulated within the virtual crystal approximation, and particular features of the appearance of an exciton condensate in a nonideal system are studied based on this simulation. Conditions under which an BEC of light and dark excitons can appear are revealed.