Double 2 s-1 s resonance in LO-phonon-assisted secondary emission of excitions in CdTe/(Cd, Mn) Te MQW structures.

We report on the observation of the doubly resonant secondary emission involving 2 s and 1 s exciton states. The resonance conditions have been realized in CdTe/CdMn Te quantum well structures by magnetic-field tuning of the 2 s-1 s energy spacing to the LO-phonon energy. Theoretical analysis shows the doubly resonant process to be indirect, with hot 1 s excitons acting as intermediate states. It is concluded that the resonance width of 2.6 meV gives the 2 s-exciton homogeneous linewidth governed by elastic scattering into the hot 1 s exciton states. [ABSTRACT FROM AUTHOR]