Magnetic bimerons as skyrmion analogues in in-plane magnets

TLDR

A magnetic bimeron is a pair of merons, the in‑plane analogue of a skyrmion. The study predicts single magnetic bimerons and bimeron crystals and compares their electrodynamics to skyrmion analogues. We show that bimeron crystals can be stabilized in frustrated magnets via the Dzyaloshinskii‑Moriya interaction and use micromagnetic simulations to demonstrate their current‑driven motion in in‑plane racetrack devices. Bimeron crystals exhibit a pure topological Hall effect, unlike skyrmion crystals, and can serve as information bits in racetrack devices with current‑driven motion.

Abstract

A magnetic bimeron is a pair of two merons and can be understood as the in-plane magnetized version of a skyrmion. Here we theoretically predict the existence of single magnetic bimerons as well as bimeron crystals, and compare the emergent electrodynamics of bimerons with their skyrmion analogues. We show that bimeron crystals can be stabilized in frustrated magnets and analyze what crystal structure can stabilize bimerons or bimeron crystals via the Dzyaloshinskii-Moriya interaction. We point out that bimeron crystals, in contrast to skyrmion crystals, allow for the detection of a pure topological Hall effect. By means of micromagnetic simulations, we show that bimerons can be used as bits of information in in-plane magnetized racetrack devices, where they allow for current-driven motion for torque orientations that leave skyrmions in out-of-plane magnets stationary.