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Very large magnetoresistance in lateral ferromagnetic (Ga,Mn)As wires with nanoconstrictions

C. Ruester·T. Borzenko·C. Gould·G. Schmidt·L. W. Molenkamp·X. Liu·T. J. Wojtowicz·J. K. Furdyna·Z. G. Yu·M. E. Flatte
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Abstract

We have fabricated (Ga,Mn)As nanostructures in which domain walls can be pinned by sub-10 nm constrictions. Controlled by shape anisotropy, we can switch the regions on either side of the constriction to either parallel or antiparallel magnetization. All samples exhibit a positive magnetoresistance, consistent with domain-wall trapping. For metallic samples we find a magnetoresistance up to 8%, which can be understood from spin accumulation. In samples where, due to depletion at the constriction, a tunnel barrier is formed, we observe a magnetoresistance of up to 2000 %.

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C. Ruester, T. Borzenko, C. Gould, G. Schmidt, L. W. Molenkamp, X. Liu, T. J. Wojtowicz, J. K. Furdyna, Z. G. Yu, M. E. Flatte. 2003-08-19. Very large magnetoresistance in lateral ferromagnetic (Ga,Mn)As wires with nanoconstrictions. https://doi.org/10.1103/physrevlett.91.216602

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