中国物理B ›› 2025, Vol. 34 ›› Issue (10): 107505-107505.doi: 10.1088/1674-1056/addaa4

所属专题： SPECIAL TOPIC — Advanced magnonics

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Micromagnetic study of the dipolar-exchange spin waves in antiferromagnetic thin films

Jiongjie Wang(王炯杰)1 and Jiang Xiao(肖江)1,2,3,4,†   

  1. 1 Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China;
    2 Institute for Nanoelectronics Devices and Quantum Computing, Fudan University, Shanghai 200433, China;
    3 Shanghai Research Center for Quantum Sciences, Shanghai 201315, China;
    4 Hefei National Laboratory, Hefei 230088, China
  • 收稿日期:2025-03-28 修回日期:2025-05-19 接受日期:2025-05-20 发布日期:2025-10-15
  • 通讯作者: Jiang Xiao E-mail:xiaojiang@fudan.edu.cn
  • 基金资助:
    This project was supported by the National Natural Science Foundation of China (Grant No. 12474110), the National Key Research and Development Program of China (Grant No. 2022YFA1403300), the Innovation Program for Quantum Science and Technology (Grant No. 2024ZD0300103), and the Shanghai Municipal Science and Technology Major Project (Grant No. 2019SHZDZX01).

Micromagnetic study of the dipolar-exchange spin waves in antiferromagnetic thin films

Jiongjie Wang(王炯杰)1 and Jiang Xiao(肖江)1,2,3,4,†   

  1. 1 Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China;
    2 Institute for Nanoelectronics Devices and Quantum Computing, Fudan University, Shanghai 200433, China;
    3 Shanghai Research Center for Quantum Sciences, Shanghai 201315, China;
    4 Hefei National Laboratory, Hefei 230088, China
  • Received:2025-03-28 Revised:2025-05-19 Accepted:2025-05-20 Published:2025-10-15
  • Contact: Jiang Xiao E-mail:xiaojiang@fudan.edu.cn
  • Supported by:
    This project was supported by the National Natural Science Foundation of China (Grant No. 12474110), the National Key Research and Development Program of China (Grant No. 2022YFA1403300), the Innovation Program for Quantum Science and Technology (Grant No. 2024ZD0300103), and the Shanghai Municipal Science and Technology Major Project (Grant No. 2019SHZDZX01).

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摘要： In antiferromagnets, dipolar coupling is often disregarded due to the cancellation of magnetic moments between the two sublattices, so that the spin-wave dispersion is predominantly determined by exchange interactions. However, antiferromagnetic spin waves typically involve a slight misalignment of the magnetic moments on the sublattices, which gives rise to a small net magnetization enabling long-range dipolar coupling. In this paper, we investigate the role of dipolar coupling in spin-wave excitations and its influence on the resulting dispersion. Our findings show that: (i) when the Néel vector is perpendicular to the film plane or lies within the film plane and parallel to the wave vector, the dispersion branches can be divided into two groups: those unaffected by the dipolar field and those influenced by it. In these cases, the total magnetic moment remains linearly polarized, but the polarization directions differ between the two types of branches; (ii) when the Néel vector lies in the film plane and is perpendicular to the wave vector, the dipolar interactions affect both types of dispersion branches, leading to their hybridization. This hybridization alters the polarization of the magnetic moment, resulting in elliptical polarization.

关键词: spin waves, spintronics, antiferromagnetics, magnetic properties of thin films

Abstract: In antiferromagnets, dipolar coupling is often disregarded due to the cancellation of magnetic moments between the two sublattices, so that the spin-wave dispersion is predominantly determined by exchange interactions. However, antiferromagnetic spin waves typically involve a slight misalignment of the magnetic moments on the sublattices, which gives rise to a small net magnetization enabling long-range dipolar coupling. In this paper, we investigate the role of dipolar coupling in spin-wave excitations and its influence on the resulting dispersion. Our findings show that: (i) when the Néel vector is perpendicular to the film plane or lies within the film plane and parallel to the wave vector, the dispersion branches can be divided into two groups: those unaffected by the dipolar field and those influenced by it. In these cases, the total magnetic moment remains linearly polarized, but the polarization directions differ between the two types of branches; (ii) when the Néel vector lies in the film plane and is perpendicular to the wave vector, the dipolar interactions affect both types of dispersion branches, leading to their hybridization. This hybridization alters the polarization of the magnetic moment, resulting in elliptical polarization.

Key words: spin waves, spintronics, antiferromagnetics, magnetic properties of thin films

中图分类号:  (Spin waves)

  • 75.30.Ds
85.75.-d (Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields) 75.50.Ee (Antiferromagnetics) 75.70.-i (Magnetic properties of thin films, surfaces, and interfaces)