Creation of a Chiral Bobber Lattice in Helimagnet-Multilayer Heterostructures

TL;DR

This paper demonstrates the creation and observation of a stable chiral bobber lattice in a heterostructure, introducing a new mechanism and a novel characterization technique for these three-dimensional magnetic configurations.

Contribution

It presents a new method to generate a stable chiral bobber lattice using skyrmion species proximity and introduces magnetic truncation rod analysis for unambiguous detection.

Findings

Exotic chiral bobber lattice observed in Cu2OSeO3 heterostructure

New creation mechanism via skyrmion species proximity

Development of magnetic truncation rod analysis technique

Abstract

A chiral bobber is a localized three-dimensional magnetization configuration, terminated by a singularity. Chiral bobbers coexist with magnetic skyrmions in chiral magnets, lending themselves to new types of skyrmion-complementary bits of information. However, the on-demand creation of bobbers, as well as their direct observation remained elusive. Here, we introduce a new mechanism for creating a stable chiral bobber lattice state via the proximity of two skyrmion species with comparable size. This effect is experimentally demonstrated in a Cu$_2$OSeO$_3$/[Ta/CoFeB/MgO]$_4$ heterostructure in which an exotic bobber lattice state emerges in the phase diagram of Cu$_2$OSeO$_3$. To unambiguously reveal the existence of the chiral bobber lattice state, we have developed a novel characterization technique, magnetic truncation rod analysis, which is based on resonant elastic x-ray scattering.