Bosonic stimulation of cold excitons in a harmonic potential trap in CuimageO

A high-density cold exciton gas is generated in a harmonic potential trap by two-photon resonance excitation of CuimageO at 2 K. Strongly localized light signal is observed at the bottom of the potential trap when the exciton density exceeds 10image cmimage. The possibility of bosonic stimulation of excitons from the trap rim to the bottom is discussed in connection with the origin of the light signal.