A novel method for the injection and manipulation of magnetic charge states in nanostructures

TL;DR

This paper introduces a simple, versatile technique using a magnetic force microscope tip to write and manipulate magnetic charge states, including 360-degree domain walls, in ferromagnetic nanowires, advancing nanoscale magnetic control.

Contribution

It presents a novel, straightforward method for controlling magnetic states in nanostructures using a magnetic force microscope tip, applicable to various nanowire architectures.

Findings

Successful injection and manipulation of 360-degree domain walls in Py and Co nanowires.

Method demonstrated to be effective across different nanowire designs.

Supported by micromagnetic simulations confirming the experimental results.

Abstract

Realising the promise of next-generation magnetic nanotechnologies is contingent on the development of novel methods for controlling magnetic states at the nanoscale. There is currently demand for simple and flexible techniques to access exotic magnetisation states without convoluted fabrication and application processes. 360 degree domain walls (metastable twists in magnetisation separating two domains with parallel magnetisation) are one such state, which is currently of great interest in data storage and magnonics. Here, we demonstrate a straightforward and powerful process whereby a moving magnetic charge, provided experimentally by a magnetic force microscope tip, can write and manipulate magnetic charge states in ferromagnetic nanowires. The method is applicable to a wide range of nanowire architectures with considerable benefits over existing techniques. We confirm the method's efficacy via the injection and spatial manipulation of 360 degree domain walls in Py and Co nanowires. Experimental results are supported by micromagnetic simulations of the tip-nanowire interaction.