Neutral and positively charged excitons: A magneto-optical study of a p-doped Cd12xMnxTe quantum well
نویسنده
چکیده
We present a systematic study of optical transitions in a modulation doped Cd12xMnxTe quantum well with variable concentration of the hole gas. Using a semimagnetic semiconductor as the quantum well material allowed us to control independently the total hole concentration and its distribution between the two spin subbands ~by a small magnetic field!. Therefore, in transmission experiment we analyze population effects and distinguish the influence of spin-independent effects ~screening! from spin-dependent ones ~phase-space filling and intensity stealing!. The observed variation of the exciton ~X! and charged exciton (X) oscillator strengths can be accounted for assuming that the influence of phase-space filling is negligible and the variation of oscillator strength due to screening is found to be similar for both exciton species. We also show that the X dissociation energy significantly increases with the population of preexisting carriers with the appropriate spin. @S0163-1829~99!09147-X#
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