Boundary conditions and Berry phase in magnetic nanostructures

Authors

A. Ullah, University of Nebraska - LincolnFollow
B. Balamurugan, University of Nebraska-LincolnFollow
W. Zhang, University of Nebraska - LincolnFollow
D. J. Sellmyer, University of Nebraska - LincolnFollow
R. Skomski, University of Nebraska-LincolnFollow

Date of this Version

2019

Citation

AIP Advances 9, 125049 (2019)

Comments

© Author(s) 2019

Open access

doi: 10.1063/1.5130477

Abstract

The effect of micromagnetic boundary conditions on the Berry curvature and topological Hall effect in granular nanostructures is investi- gated by model calculations. Both free surfaces and grain boundaries between interacting particles or grains affect the spin structure. The Dzyaloshinskii-Moriya interactions yield corrections to the Erdmann-Weierstrass boundary conditions, but the Berry curvature remains an exclusive functional of the local spin structure, which greatly simplifies the treatment of nanostructures. An explicit example is a model nanostructure with cylindrical symmetry whose spin structure is described by Bessel function and which yields a mean-field-type Hall-effect contribution that can be related to magnetic-force-microscopy images.