Mechanism of carrier-induced ferromagnetism in magnetic semiconductors

Abstract

Taking into account both random impurity distribution and thermal fluctuations of localized spins, we have performed a model calculation for the carrier (hole) state in Ga${}_{1-x}$Mn${}_x$As by using the coherent potential approximation (CPA). The result reveals that a {\it p}-hole in the band tail of Ga${}_{1-x}$Mn${}_x$As is not like a free carrier but is rather virtually bounded to impurity sites. The carrier spin strongly couples to the localized {\it d} spins on Mn ions. The hopping of the carrier among Mn sites causes the ferromagnetic ordering of the localized spins through the double-exchange mechanism. The Curie temperature obtained by using conventional parameters agrees well with the experimental result.

7 pages, 4 figures

References in corpus (1)

• Electronic structure of In${}_{1-x}$Mn${}_x$As studied by photoemission spectroscopy: Comparison with Ga${}_{1-x}$Mn${}_x$As

Cited by in corpus (5)

• Disorder effects in diluted magnetic semiconductors
• Influence of non-local exchange on RKKY interactions in III-V diluted magnetic semiconductors
• Ultrahigh-Field Hole Cyclotron Resonance Absorption in InMnAs Films
• Chemical and magnetic impurity effects on electronic properties of semiconductor quantum wires
• Carrier States and Ferromagnetism in Diluted Magnetic Semiconductors