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Updated: Aug 29, 2026

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
Published on: July 20, 2022
Very large magnetoresistance in lateral ferromagnetic (Ga,Mn)as wires with nanoconstrictions
C Rüster1, T Borzenko, C Gould
1Physikalisches Institut (EP3), Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
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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