Carrier-induced spin splitting of an individual magnetic atom embedded in a quantum dot

摘要

The influence of the number of confined carriers on the spin splitting of a single magnetic ion (Mn~(2+)) embedded in a semiconductor quantum dot is evidenced. Investigating both the biexciton and the exciton transitions in the same Mn-doped quantum dot, we analyze the impact of the Mn-exciton exchange interaction on the fine structure of the quantum dot emission. A single electron-hole pair is enough to induce a spontaneous splitting of the exciton-Mn system. The injection of a second electron-hole pair cancels the exchange interaction with the Mn ion and the Mn spin splitting is significantly reduced. A detailed analysis of the biexciton-Mn transitions reveals that the carriers' orbital wave functions are perturbed by the interaction with the magnetic ion.