Nonreciprocal dynamics of ferrimagnetic bimerons

TL;DR

This paper presents a theoretical study on the nonreciprocal movement of ferrimagnetic bimerons induced by spin currents, revealing their high-speed motion and absence of skyrmion Hall effect at specific points, with implications for spintronic devices.

Contribution

It introduces the first detailed analysis of nonreciprocal dynamics of asymmetrical ferrimagnetic bimerons driven by spin currents, including analytical and simulation results.

Findings

Ferrimagnetic bimerons can reach speeds of kilometers per second.

They do not exhibit the skyrmion Hall effect at the angular momentum compensation point.

Nonreciprocal transport is caused by structural asymmetry of the bimerons.

Abstract

Magnetic bimerons are topologically nontrivial spin textures in in-plane easy-axis magnets, which can be used as particle-like information carriers. Here, we report a theoretical study on the nonreciprocal dynamics of asymmetrical ferrimagnetic (FiM) bimerons induced by spin currents. The FiM bimerons have the ability to move at a speed of kilometers per second and do not show the skyrmion Hall effect at the angular momentum compensation point. Our micromagnetic simulations and analytical results demonstrate that spin currents are able to induce the nonreciprocal transport and a drift motion of the FiM bimeron even if the system is at the angular momentum compensation point. By analyzing the current-induced effective fields, we find that the nonreciprocal transport is attributed to the asymmetry of the bimeron structure. Our results are useful for understanding the physics of bimerons in ferrimagnets and may provide guidelines for building bimeron-based spintronic devices.