Coherently photoinduced ferromagnetism in diluted magnetic semiconductors
Abstract
Local spins in undoped diluted magnetic semiconductors do not normally order. We predict that the moments will align spontaneously when the sample is illuminated by intense sub-bandgap laser radiation. The mechanism for photo-induced ferromagnetism is the coherence between conduction and valence bands induced by the light, that leads to an optical exchange interaction. The induced magnetism is extinguished by switching off the laser, allowing the magnetic state to be altered on ns times scales, in contrast to magnetism induced by incoherent optical excitation of carriers. The ferromagnetic critical temperature TC depends both on the properties of the material and on the frequency and intensity of the laser and could be above 1 K.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARA26012F