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

• Published in: Chinese physics B 2016-10, Vol.25 (10), p.378-385
• Main Author: 周博臻 周斌
• Format: Article
• Language: English
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/25/10/107401

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.