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arXiv 0811.4585cond-mat.mtrl-sci
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铁磁(Ga,Mn)As的弱局域化理论

Theory of Weak Localization in Ferromagnetic (Ga,Mn)As

Ion Garate, Jairo Sinova, T. Jungwirth, A. H. MacDonald

摘要:

利用无序价带空穴通过p-d动力学交换相互作用耦合到局域Mn磁矩的模型,研究了(Ga,Mn)As铁磁半导体电导率的量子干涉修正.我们发现,在Mn浓度超过1%的量子干涉校正导致负磁阻,即弱本地化(WL),而不是弱反本地化(WAL)。我们的工作突出了(Ga,Mn)As和以前研究的玩具模型系统之间的关键质的差异,并指出了铁磁状态下的交换分裂转换价带WAL到WL的机制。我们评论最近的实验研究和理论分析的低温磁电阻在(Ga,Mn)As已被不同的解释为意味着WL和WAL和需要一个杂质带的解释在金属(Ga,Mn)As的运输。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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