Dynamics of the localized spins interacting with two-dimensional electron gas: Coexistence of mixed and pure modes

摘要

Time-resolved Kerr rotation experiments show that two kinds of spin modes exist in diluted magnetic semiconductor quantum wells: (ⅰ) strongly coupled electron-magnetic ion spin excitations and (ⅱ) excitations of magnetic ion spin subsystem decoupled from electron spins. The coexistence of these two kinds of spin precession modes cannot be understood in terms of average spins but requires a description, which goes beyond the mean-field approximation.