Domain Wall Networks as Skyrmion Crystals in Chiral Magnets

TL;DR

This paper theoretically demonstrates that chiral magnets with square anisotropy can host stable domain wall networks that form skyrmion crystals, with tunable domain sizes influenced by external magnetic fields.

Contribution

It reveals the existence of stable domain wall networks as skyrmion crystals in chiral magnets with square anisotropy, expanding understanding of topological magnetic states.

Findings

Domain wall junctions act as skyrmions with half topological charge.

The phase diagram includes skyrmion lattices, chiral soliton lattices, and ferromagnetic states.

External magnetic fields can tune the size of domains in the domain wall network.

Abstract

We theoretically investigate the ground states of a chiral magnet with a square anisotropy and show that it supports domain wall networks as stable ground states. A domain wall junction in the domain wall network turns out to be a skyrmion with half topological charge and, therefore, the found domain wall network has a second topological nature, a skyrmion crystal. More specifically, we present a ground-state phase diagram of the chiral magnet with varying anisotropy parameters consisting of skyrmion lattices, chiral soliton lattices, and ferromagnetic states. In the presence of the square anisotropy, the skyrmion crystal forms a domain wall network. The size of domains in the domain wall network is shown to be tunable by an external magnetic field, offering a way to realize experimentally detectable domain wall networks.