中国物理B ›› 2016, Vol. 25 ›› Issue (10): 107401-107401.doi: 10.1088/1674-1056/25/10/107401

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

Topological phase transition in a ladder of the dimerized Kitaev superconductor chains

Bo-Zhen Zhou(周博臻), Bin Zhou(周斌)   

  1. Department of Physics, Hubei University, Wuhan 430062, China
  • 收稿日期:2016-05-03 修回日期:2016-06-21 出版日期:2016-10-05 发布日期:2016-10-05
  • 通讯作者: Bin Zhou E-mail:binzhou@hubu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11274102), the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-11-0960), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20134208110001).

Topological phase transition in a ladder of the dimerized Kitaev superconductor chains

Bo-Zhen Zhou(周博臻), Bin Zhou(周斌)   

  1. Department of Physics, Hubei University, Wuhan 430062, China
  • Received:2016-05-03 Revised:2016-06-21 Online:2016-10-05 Published:2016-10-05
  • Contact: Bin Zhou E-mail:binzhou@hubu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11274102), the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-11-0960), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20134208110001).

摘要: We investigate the topological properties of a ladder model of the dimerized Kitaev superconductor chains. The topological class of the system is determined by the relative phase θ between the inter- and intra-chain superconducting pairing. One topological class is the class BDI characterized by the Z index, and the other is the class D characterized by the Z2 index. For the two different topological classes, the topological phase diagrams of the system are presented by calculating two different topological numbers, i.e., the Z index winding number W and the Z2 index Majorana number M, respectively. In the case of θ =0, the topological class belongs to the class BDI, multiple topological phase transitions accompanying the variation of the number of Majorana zero modes are observed. In the case of θ =π/2 it belongs to the class D. Our results show that for the given value of dimerization, the topologically nontrivial and trivial phases alternate with the variation of chemical potential.

关键词: Majorana zero modes, topological class, topological phase transition

Abstract: We investigate the topological properties of a ladder model of the dimerized Kitaev superconductor chains. The topological class of the system is determined by the relative phase θ between the inter- and intra-chain superconducting pairing. One topological class is the class BDI characterized by the Z index, and the other is the class D characterized by the Z2 index. For the two different topological classes, the topological phase diagrams of the system are presented by calculating two different topological numbers, i.e., the Z index winding number W and the Z2 index Majorana number M, respectively. In the case of θ =0, the topological class belongs to the class BDI, multiple topological phase transitions accompanying the variation of the number of Majorana zero modes are observed. In the case of θ =π/2 it belongs to the class D. Our results show that for the given value of dimerization, the topologically nontrivial and trivial phases alternate with the variation of chemical potential.

Key words: Majorana zero modes, topological class, topological phase transition

中图分类号:  (Theories and models of superconducting state)

  • 74.20.-z
74.78.-w (Superconducting films and low-dimensional structures) 71.10.Pm (Fermions in reduced dimensions (anyons, composite fermions, Luttinger liquid, etc.))