中国物理B ›› 2018, Vol. 27 ›› Issue (9): 97501-097501.doi: 10.1088/1674-1056/27/9/097501

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Modulational instability, quantum breathers and two-breathers in a frustrated ferromagnetic spin lattice under an external magnetic field

Wanhan Su(苏琬涵), Jiayu Xie(谢家玉), Tianle Wu(吴天乐), Bing Tang(唐炳)   

  1. College of Physics, Mechanical and Electrical Engineering, Jishou University, Jishou 416000, China
  • 收稿日期:2018-05-27 修回日期:2018-06-24 出版日期:2018-09-05 发布日期:2018-09-05
  • 通讯作者: Bing Tang E-mail:bingtangphy@jsu.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11604121), the Scientific Research Fund of Hunan Provincial Education Department, China (Grant Nos. 16B210 and 16A170), and the Natural Science Fund Project of Jishou University, China (Grant No. jdx17036).

Modulational instability, quantum breathers and two-breathers in a frustrated ferromagnetic spin lattice under an external magnetic field

Wanhan Su(苏琬涵), Jiayu Xie(谢家玉), Tianle Wu(吴天乐), Bing Tang(唐炳)   

  1. College of Physics, Mechanical and Electrical Engineering, Jishou University, Jishou 416000, China
  • Received:2018-05-27 Revised:2018-06-24 Online:2018-09-05 Published:2018-09-05
  • Contact: Bing Tang E-mail:bingtangphy@jsu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11604121), the Scientific Research Fund of Hunan Provincial Education Department, China (Grant Nos. 16B210 and 16A170), and the Natural Science Fund Project of Jishou University, China (Grant No. jdx17036).

摘要:

The modulational instability, quantum breathers and two-breathers in a frustrated easy-axis ferromagnetic zig-zag chain under an external magnetic field are investigated within the Hartree approximation. By means of a linear stability analysis, we analytically study the discrete modulational instability and analyze the effect of the frustration strength on the discrete modulational instability region. Using the results from the discrete modulational instability analysis, the presence conditions of those stationary bright type localized solutions are presented. On the other hand, we obtain the analytical expressions for the stationary bright localized solutions and analyze the effect of the frustration on their emergence conditions. By taking advantage of these bright type single-magnon bound wave functions obtained, quantum breather states in the present frustrated ferromagnetic zig-zag lattice are constructed. What is more, the analytical forms for quantum two-breather states are also obtained. In particular, the energy level formulas of quantum breathers and two-breathers are derived.

关键词: quantum breathers, quantum two-breathers, modulational instability, frustrated ferromagnetic chains

Abstract:

The modulational instability, quantum breathers and two-breathers in a frustrated easy-axis ferromagnetic zig-zag chain under an external magnetic field are investigated within the Hartree approximation. By means of a linear stability analysis, we analytically study the discrete modulational instability and analyze the effect of the frustration strength on the discrete modulational instability region. Using the results from the discrete modulational instability analysis, the presence conditions of those stationary bright type localized solutions are presented. On the other hand, we obtain the analytical expressions for the stationary bright localized solutions and analyze the effect of the frustration on their emergence conditions. By taking advantage of these bright type single-magnon bound wave functions obtained, quantum breather states in the present frustrated ferromagnetic zig-zag lattice are constructed. What is more, the analytical forms for quantum two-breather states are also obtained. In particular, the energy level formulas of quantum breathers and two-breathers are derived.

Key words: quantum breathers, quantum two-breathers, modulational instability, frustrated ferromagnetic chains

中图分类号:  (Quantized spin models, including quantum spin frustration)

  • 75.10.Jm
75.30.Ds (Spin waves) 63.20.Pw (Localized modes)