中国物理B ›› 2020, Vol. 29 ›› Issue (6): 67501-067501.doi: 10.1088/1674-1056/ab8886

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

Exact solution of a topological spin ring with an impurity

Xu-Chu Huang(黄旭初), Yi-Hua Song(宋艺华), Yi Sun(孙毅)   

  1. Department of Physics, Changji University, Changji 830011, China
  • 收稿日期:2019-10-26 修回日期:2020-03-17 出版日期:2020-06-05 发布日期:2020-06-05
  • 通讯作者: Yi-Hua Song E-mail:y.quantumage@163.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11664001).

Exact solution of a topological spin ring with an impurity

Xu-Chu Huang(黄旭初), Yi-Hua Song(宋艺华), Yi Sun(孙毅)   

  1. Department of Physics, Changji University, Changji 830011, China
  • Received:2019-10-26 Revised:2020-03-17 Online:2020-06-05 Published:2020-06-05
  • Contact: Yi-Hua Song E-mail:y.quantumage@163.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11664001).

摘要: The spin-1/2 Heisenberg chain coupled to a spin-S impurity moment with anti-periodic boundary condition is studied via the off-diagonal Bethe ansatz method. The twisted boundary breaks the U(1) symmetry of the system, which leads to that the spin ring with impurity can not be solved by the conventional Bethe ansatz methods. By combining the properties of the R-matrix, the transfer matrix, and the quantum determinant, we derive the T-Q relation and the corresponding Bethe ansatz equations. The residual magnetizations of the ground states and the impurity specific heat are investigated. It is found that the residual magnetizations in this model strongly depend on the constraint of the topological boundary condition, the inhomogeneity of the impurity comparing with the hosts could depress the impurity specific heat in the thermodynamic limit. This method can be expand to other integrable impurity models without U(1) symmetry.

关键词: Bethe ansatz, impurity, topological spin ring

Abstract: The spin-1/2 Heisenberg chain coupled to a spin-S impurity moment with anti-periodic boundary condition is studied via the off-diagonal Bethe ansatz method. The twisted boundary breaks the U(1) symmetry of the system, which leads to that the spin ring with impurity can not be solved by the conventional Bethe ansatz methods. By combining the properties of the R-matrix, the transfer matrix, and the quantum determinant, we derive the T-Q relation and the corresponding Bethe ansatz equations. The residual magnetizations of the ground states and the impurity specific heat are investigated. It is found that the residual magnetizations in this model strongly depend on the constraint of the topological boundary condition, the inhomogeneity of the impurity comparing with the hosts could depress the impurity specific heat in the thermodynamic limit. This method can be expand to other integrable impurity models without U(1) symmetry.

Key words: Bethe ansatz, impurity, topological spin ring

中图分类号:  (Magnetic impurity interactions)

  • 75.30.Hx
02.30.Ik (Integrable systems) 72.10.Fk (Scattering by point defects, dislocations, surfaces, and other imperfections (including Kondo effect))