Spectroscopy and Characteristic Energies of a Spin-Polarized Hole Gas

Abstract

The giant Zeeman splitting present in a quantum well made of a diluted magnetic semiconductor allows us not only to completely polarize the hole gas it contains, but also to destabilize the charged exciton singlet state (which emits at small spin splitting) in favor of an electron‐hole state involving a majority‐spin hole. At low carrier density, this is the neutral exciton, and at higher carrier density, a weakly correlated electron‐hole pair. By comparing spectra recorder under different conditions, we access different characteristic energies such as the true binding energy of the charged exciton, the spin splitting necessary to fully polarize the hole gas, and the energy of excited states of the hole gas which are involved in optical transitions.