Refined Majorana phase diagram in topological insulator-superconductor hybrid system
Abstract
The edge state of the topological insulator coupled to a superconductor system is able to simulate the Majorana fermion in zero energy mode since the Kitaev-type pairing is induced by exchanging quasi-excitations in electron tunneling. However, the present study has revealed that this physical simulation is not valid for a larger surface gap, which is the energy gap of the insulator's surface states. To address this issue, a refined pairing term that depends on the surface gap has been obtained as a second-order effect of the proximity effect, whereas the lowest order produces a constant pairing strength. By carefully considering the dependence of pairing strength on the surface gap, the Majorana phase diagram is re-achieved and a significant difference from previous work is observed, where the pairing strength was assumed to be independent of the surface gap and resulted in a conical phase boundary.
Keywords
Cite
@article{arxiv.2303.14659,
title = {Refined Majorana phase diagram in topological insulator-superconductor hybrid system},
author = {Xin Yue and Guo-Jian Qiao and C. P. Sun},
journal= {arXiv preprint arXiv:2303.14659},
year = {2025}
}