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arXiv · 0806.2590

Metal-insulator transition and giant anisotropic magnetoresistance in ultra thin (Ga,Mn)As

R. R. Gareev·A. Petukhov·M. Schlapps·M. Doeppe·J. Sadowski·M. Sperl·W. Wegscheider
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Abstract

MBE-grown, 5 nm-thick annealed Ga0.95Mn0.05As films with Tc~90K demonstrate transition from metallic to insulating state below To~10K, where sheet resistances Rsh~h/e2 and both longitudinal Rxx and transverse Rxy components become comparable. Below metal-insulator transition we found giant anisotropic magnetoresistance (GAMR), which depends on orientation of magnetization to crystallographic axes and manifests itself in positive magnetoresistance near 50% for Rxx at T=1.7K, H//[110] crystallographic direction and parallel to current in contrast to smaller and negative magnetoresistance for H// direction. We connect GAMR with anisotropic spin-orbit interaction resulting in formation of high- and low- resistance states with different localization along non-equivalent easy axes.

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R. R. Gareev, A. Petukhov, M. Schlapps, M. Doeppe, J. Sadowski, M. Sperl, W. Wegscheider. 2008-06-16. Metal-insulator transition and giant anisotropic magnetoresistance in ultra thin (Ga,Mn)As. https://arxiv.org/abs/0806.2590

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