Non-planar geometrical effects on the magnetoelectrical signal in a three-dimensional nanomagnetic circuit

TL;DR

This study explores how complex three-dimensional geometries in nanomagnetic devices influence magnetoelectrical signals, revealing unique angular dependencies and the significant role of noncollinear demagnetising fields through combined experimental and simulation approaches.

Contribution

It provides the first detailed analysis of 3D geometrical effects on magnetoelectrical phenomena in nanostructures using integrated measurements and modeling.

Findings

Unusual angular dependences of magnetotransport effects like the anomalous Hall effect.

Identification of the strong influence of noncollinear demagnetising fields.

Demonstration of the role of 3D geometry in shaping magnetoelectrical signals.

Abstract

Expanding nanomagnetism and spintronics into three dimensions (3D) offers great opportunities for both fundamental and technological studies. However, probing the influence of complex 3D geometries on magnetoelectrical phenomena poses important experimental and theoretical challenges. In this work, we investigate the magnetoelectrical signals of a ferromagnetic 3D nanodevice integrated into a microelectronic circuit using direct-write nanofabrication. Due to the 3D vectorial nature of both electrical current and magnetisation, a complex superposition of several magnetoelectrical effects takes place. By performing electrical measurements under the application of 3D magnetic fields, in combination with macrospin simulations and finite element modelling, we disentangle the superimposed effects, finding how a 3D geometry leads to unusual angular dependences of well-known magnetotransport effects such as the anomalous Hall effect. Crucially, our analysis also reveals a strong role of the noncollinear demagnetising fields intrinsic to 3D nanostructures, which results in an angular dependent magnon magnetoresistance contributing strongly to the total magnetoelectrical signal. These findings are key to the understanding of 3D spintronic systems and underpin further fundamental and device-based studies.