Specific features of the indirect exciton luminescence line in GaAs/AlxGa1-xAs double quantum wells - art. no. 045313

A study is reported of the low temperature ( T< 30 K) photoluminescence fro m space-indirect excitons (IX) in GaAs/AlxGa1-xAs double quantum wells at p umping density P and external electric field V-dc. At certain values of the external parameters (P, T, and V-dc) a part of the spectral profile of the IX line shows an enormous increase (shot) in photoluminescence intensity ( three times), fluctuating with time on a characteristic scale of tens of se conds. This anomalous behavior is explained in terms of the theoretical mod el of the Bose-Einstein condensation occurring in a system of two-dimension al bosons that has, in addition to the extended (free) states, some discret e energy spectrum below the bottom of the free zone.