Skyrmionic magnetization configurations at chiral magnet/ferromagnet heterostructures

TL;DR

This paper investigates complex three-dimensional magnetization configurations at chiral magnet/ferromagnet heterostructures, revealing the emergence and stability of exotic structures like skyrmion cones and twisted helices due to interfacial interactions.

Contribution

It introduces a variational framework to analyze the stability of diverse magnetization configurations in CM/FM heterostructures, highlighting novel 3D structures and emergent magnetic fields.

Findings

Various stable 3D magnetization configurations identified.

Exotic structures such as skyrmion cones and sideways skyrmions found.

Nontrivial emergent magnetic fields associated with these configurations.

Abstract

We consider magnetization configurations at chiral magnet (CM)/ferromagnet (FM) heterostructures. In the CM, magnetic skyrmions and spin helices emerge due to the Dzyaloshinskii-Moriya interaction, which then penetrate into the adjacent FM. However, because the non-uniform magnetization structures are energetically unfavorable in the FM, the penetrated magnetization structures are deformed, resulting in exotic three-dimensional configurations, such as skyrmion cones, sideways skyrmions, and twisted helices and skyrmions. We discuss the stability of possible magnetization configurations at the CM/FM and CM/FM/CM hybrid structures within the framework of the variational method, and find that various magnetization configurations appear in the ground state, some of which cause nontrivial emergent magnetic field.