Sa. Moskalenko et Vr. Misko, INDUCED BOSE-EINSTEIN CONDENSATION OF BIEXCITONS AND EXCITONS IN THE FIELD OF LASER-RADIATION, UKRAINSKII FIZICHESKII ZHURNAL, 37(12), 1992, pp. 1812-1818
The elementary excitations energetic spectrum of the system of biexcit
ons in the presence of Bose-condensed quasiparticles induced by the la
ser radiation due to two-photon transitions was investigated. It was s
hown, that in some regions of wave vectors the instabilities in the en
ergetic spectrum can appear. They depend essentially on the laser freq
uency detuning and light intensity. The same result is true for the sy
stem of excitons in the presence of resonant laser radiation which ind
uces the corresponding Bose condensed state due to one-photon transiti
ons.