Theory of weak localization in ferromagnetic (Ga,Mn)As

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Title:	Theory of weak localization in ferromagnetic (Ga,Mn)As
Author:	Garate, Ion; Sinova, Jairo; Jungwirth, T.; MacDonald, A. H.
Abstract:	We study quantum interference corrections to the conductivity in (Ga,Mn)As ferromagnetic semiconductors using a model with disordered valence-band holes coupled to localized Mn moments through a p-d kinetic-exchange interaction. We find that at Mn concentrations above 1% quantum interference corrections lead to negative magnetoresistance, i.e., to weak localization (WL) rather than weak antilocalization (WAL). Our work highlights key qualitative differences between (Ga,Mn)As and previously studied toy-model systems and pinpoints the mechanism by which exchange splitting in the ferromagnetic state converts valence-band WAL into WL. We comment on recent experimental studies and theoretical analyses of low-temperature magnetoresistance in (Ga,Mn)As which have been variously interpreted as implying both WL and WAL and as requiring an impurity-band interpretation of transport in metallic (Ga,Mn)As.
Description:	Journals published by the American Physical Society can be found at http://journals.aps.org/
Publisher:	American Physical Society
Subject:	electrical conductivity exchange interactions (electron) ferromagnetic materials gallium arsenide magnetic semiconductors magnetoresistance manganese compounds quantum interference phenomena weak localisation ELECTRON-ELECTRON INTERACTIONS QUANTUM-WELLS SEMICONDUCTORS FILMS TRANSPORT SYSTEMS ABSENCE Physics
Department:	Physics and Astronomy
URI:	http://dx.doi.org/10.1103/PhysRevB.79.155207
Date:	2009