Subpicosecond dynamical renormalization of spin-polarized electron–hole plasma in Cd1−xMnxTe

Ultrafast dynamics of many-body effects induced by the spin-polarized electron–hole plasma in Cd1−xMnxTe epilayers were investigated by using femtosecond pump-probe spectroscopy in magnetic field. In the strong optical excitation limit, the renormalization of the energy gap between the spin-polarized conduction subbands and valence subbands induced by the exchange-correlation interaction, and the suppression of exciton formation due to the screening of Coulomb interaction were observed. The dynamical behaviour of these many-body effects suggests faster cooling of higher-lying spin-polarized electron–hole pairs in magnetic fields.