Determination of s-d exchange coupling in GaMnN by time-resolved Kerr rotation spectroscopy

Abstract

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 N-0 alpha = +0.23 +/- 0.02 eV, indicative of a ferromagnetic s-d exchange coupling in GaMnN. The determined N-0 alpha is consistent with the typical value found in most diluted magnetic semiconductors and reveals that GaMnN is indeed not an exception.