摘要
Coherent electron-spin dynamics in Ga1-xMnxN has been investigated by time-resolved Kerr rotation spectroscopy. The effective electron g factor shows a linear increase with the Mn concentration due to the s-d exchange coupling between the conduction electrons and the d-shell electrons of Mn3+ impurities. The magnitude and sign of the s-d exchange constant are determined precisely to be N0α=+0.23±0.02eV, indicative of a ferromagnetic s-d exchange coupling in GaMnN. The determined N0α is consistent with the typical value found in most diluted magnetic semiconductors and reveals that GaMnN is indeed not an exception.