Bloch points in nanostrips

TL;DR

This paper demonstrates through micromagnetic simulations that FeGe nanostrips with layered chiralities can host multiple coexisting Bloch points, with their number depending on the strip's geometry and type, enabling tailored magnetic configurations.

Contribution

It introduces the concept of hosting multiple Bloch points in layered nanostrips and predicts configurations for arbitrary numbers, advancing magnetic topological object control.

Findings

Multiple Bloch points can coexist in FeGe nanostrips.

The number of Bloch points depends on strip geometry and type.

An 80-Bloch-point configuration was successfully simulated.

Abstract

Complex magnetic materials hosting topologically non-trivial particle-like objects such as skyrmions are under intensive research and could fundamentally change the way we store and process data. One important class of materials are helimagnetic materials with Dzyaloshinskii-Moriya interaction. Recently, it was demonstrated that nanodisks consisting of two layers with opposite chirality can host a single stable Bloch point of two different types at the interface between the layers. Using micromagnetic simulations we show that FeGe nanostrips consisting of two layers with opposite chirality can host multiple coexisting Bloch points in an arbitrary combination of the two different types. We show that the number of Bloch points that can simultaneously coexist depends on the strip geometry and the type of the individual Bloch points. Our simulation results allow us to predict strip geometries suitable for an arbitrary number of Bloch points. We show an example of an 80-Bloch-point configuration verifying the prediction.