Coherently photo-induced ferromagnetism in diluted magnetic semiconductors

TL;DR

This paper predicts that intense sub-bandgap laser illumination can induce ferromagnetism in undoped diluted magnetic semiconductors through a light-induced coherence mechanism, with the critical temperature depending on material and laser parameters.

Contribution

It introduces a novel mechanism for photo-induced ferromagnetism based on optical coherence, expanding understanding of magnetic control via light in semiconductors.

Findings

Ferromagnetism can be induced in undoped diluted magnetic semiconductors by laser light.

The critical temperature for ferromagnetism can exceed 1 K.

The ferromagnetic transition depends on laser frequency and intensity.

Abstract

Ferromagnetism is predicted in undoped diluted magnetic semiconductors illuminated by intense sub-bandgap laser radiation . The mechanism for photo-induced ferromagnetism is coherence between conduction and valence bands induced by the light which leads to an optical exchange interaction. The ferromagnetic critical temperature T_C depends both on the properties of the material and on the frequency and intensity of the laser and could be above 1 K.