Electron spin dephasing in Mn-based II-VI diluted magnetic semiconductors
Résumé
In various manganese-based II-VI dilutedmagnetic semiconductors and their quantum structures, the measured variations of electron spin dephasing time in an external magnetic field are conflicting with the most advanced spin relaxation theory based on quantum kinetic equations. We demonstrate, by time-resolved optical spin beat measurements performed on high-mobility n-doped CdMnTe quantum wells, that these contradictions are resolved if one takes into account the electron spin dephasing induced by laser heating of the manganese spins.We then provide a test of the spin relaxation theory inMn-based quantum wells by a careful comparison with existing data, including our measurements. It turns out that the theory systematically underestimates the relaxation rates by a factor of 5.