Magnetoresistance in nanostructures: the role of nonuniform current

TL;DR

This paper presents a numerical method to calculate magnetoresistance in magnetic nanostructures, accounting for nonuniform current distributions and magnetic configurations, enhancing understanding of magnetic structure effects.

Contribution

Introduces a discretization and numerical solution approach for magnetoresistance considering local magnetization and current nonuniformity in nanostructures.

Findings

Magnetoresistance depends on local magnetization profiles.

Current distributions are non-homogeneous in different magnetic states.

Measurement of magnetoresistance can reveal magnetic structure details.

Abstract

We developed a method to calculate the magnetoresistance of magnetic nanostructures. We discretize a magnetic disk in small cells and numerically solve the Landau-Lifshitz-Gilbert (LLG) equation in order to obtain its magnetization profile. We consider a anisotropic magnetoresistance (AMR) that depends on the local magnetization as the main source of the magnetoresistance. We then use it as an input to calculate the resistance and current distribution numerically, using a relaxation method. We show how magnetoresistance measurements can be useful to obtain information on the magnetic structure. Additionally, we obtain non-homogeneous current distributions for different magnetic configurations in static and dynamical regimes.