All-optical manipulation and probing of the d-f exchange interaction in EuTe.

摘要: We demonstrate that the ultrafast fast dynamics of d–f exchange interaction, between conduction band electrons and lattice spins in EuTe, can be accessed using an all-optical technique. Our results reveal, full detail, time evolution interaction induced by a femtosecond laser pulse. Specifically, monitoring resolved reflectivity changes Kerr rotation weak light pulse reflected from surface sample, it is shown intense with photon energies higher than bandgap, triggers spin waves EuTe. The laser-induced modulate cause bandgap to oscillate amplitude reaching 1 meV, at frequencies up tens GHz. ability control monitor energy our technique opens new opportunities for manipulation magnetism time-scales.