# Modulated critical currents of spin-transfer torque-induced resistance changes in NiCu/Cu multilayered nanowires

## TL;DR

A new method fabricates magnetic nanowires that show controllable resistance changes when exposed to spin-polarized currents and magnetic fields.

## Contribution

A novel fabrication method for 3D spin valve devices using nanowires with modulated critical currents under magnetic fields.

## Key findings

- NiCu/Cu multilayered nanowires exhibit magnetic switching and excitation driven by spin-polarized currents.
- Critical currents for switching and excitation oscillate with applied magnetic fields in the nanowire devices.

## Abstract

We present a novel method combining anodic aluminum oxide template synthesis and nanolithography to selectively deposit vertically patterned magnetic nanowires on a Si substrate. With this approach we fabricated three-dimensional nanowire-based spin valve devices without the need of complex etching processes or additional spacer coating. Through this method, we successfully obtained NiCu/Cu multilayered nanowire arrays with a controlled sequence along the long axis of the nanowires. Both magnetic switching and excitation phenomena driven by spin-polarized currents were clearly demonstrated in our NiCu/Cu multilayered nanowires. Moreover, the critical currents for switching and excitation were observed to be modulated in an oscillatory manner by the magnetic field in the nanowire-based devices. We present a toy model to qualitatively explain these observations.