Realizing Majorana fermion modes in the Kitaev model

• Published in: Chinese physics B 2021-12, Vol.30 (11), p.117504-145
• Main Authors: Yang, Lu, Zhang, Jia-Xing, Liang, Shuang, Chen, Wei, Wang, Qiang-Hua
• Format: Article
• Language: English
• ISSN: 1674-1056
• DOI: 10.1088/1674-1056/ac229a

We study the possibility to realize a Majorana zero mode that is robust and may be easily manipulated for braiding in quantum computing in the ground state of the Kitaev model in this work. To achieve this we first apply a uniform [111] magnetic field to the gapless Kitaev model and turn the Kitaev model to an effective p + ip topological superconductor of spinons. We then study possible vortex binding in such system to a topologically trivial spot in the ground state. We consider two cases in the system: one is a vacancy and the other is a fully polarized spin. We show that in both cases, the system binds a vortex with the defect and a robust Majorana zero mode in the ground state at a weak uniform [111] magnetic field. The distribution and asymptotic behavior of these Majorana zero modes are studied. The Majorana zero modes in both cases decay exponentially in space, and are robust against local perturbations and other Majorana zero modes far away, which makes them promising candidates for braiding in topological quantum computing.