Current-Induced Dynamics and Chaos of Antiferromagnetic Bimerons

Laichuan Shen, Jing Xia, Xichao Zhang, Motohiko Ezawa, Oleg A. Tretiakov, Xiaoxi Liu, Guoping Zhao, and Yan Zhou

Phys. Rev. Lett. 124, 037202 – Published 23 January 2020

Abstract

A magnetic bimeron is a topologically nontrivial spin texture carrying an integer topological charge, which can be regarded as the counterpart of the skyrmion in easy-plane magnets. The controllable creation and manipulation of bimerons are crucial for practical applications based on topological spin textures. Here, we analytically and numerically study the dynamics of an antiferromagnetic bimeron driven by a spin current. Numerical simulations demonstrate that the spin current can create an isolated bimeron in the antiferromagnetic thin film via the dampinglike spin torque. The spin current can also effectively drive the antiferromagnetic bimeron without a transverse drift. The steady motion of an antiferromagnetic bimeron is analytically derived and is in good agreement with the simulation results. Also, we find that the alternating-current-induced motion of the antiferromagnetic bimeron can be described by the Duffing equation due to the presence of the nonlinear boundary-induced force. The associated chaotic behavior of the bimeron is analyzed in terms of the Lyapunov exponents. Our results demonstrate the inertial dynamics of an antiferromagnetic bimeron, and may provide useful guidelines for building future bimeron-based spintronic devices.

Received 22 May 2019
Revised 1 November 2019

DOI:https://doi.org/10.1103/PhysRevLett.124.037202

Physics Subject Headings (PhySH)

Magnetism Micromagnetism Skyrmions Spin dynamics Spin texture Spintronics

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Laichuan Shen ^1,2, Jing Xia ¹, Xichao Zhang ¹, Motohiko Ezawa ³, Oleg A. Tretiakov ⁴, Xiaoxi Liu ⁵, Guoping Zhao^2,*, and Yan Zhou ^1,†

¹School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
²College of Physics and Electronic Engineering, Sichuan Normal University, Chengdu 610068, China
³Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656, Japan
⁴School of Physics, The University of New South Wales, Sydney 2052, Australia
⁵Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan