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arXiv · 1901.03120

Topological Vortex Phase Transitions in Iron-Based Superconductors

Shengshan Qin·Lunhui Hu·Xianxin Wu·Xia Dai·Chen Fang·Fu-chun Zhang·Jiangping Hu
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Abstract

We study topological vortex phases in iron-based superconductors. Besides the previously known vortex end Majorana zero modes (MZMs) phase stemming from the existence of a three dimensional (3D) strong topological insulator state, we show that there is another topologically nontrivial phase as iron-based superconductors can be doped superconducting 3D weak topological insulators (WTIs). The vortex bound states in a superconducting 3D WTI exhibit two different types of quantum states, a robust nodal superconducting phase with pairs of bulk MZMs and a full-gap topologically nontrivial superconducting phase which has single vortex end MZM in a certain range of doping level. Moreover, we predict and summarize various topological phases in iron-based superconductors, and find that carrier doping and interlayer coupling can drive systems to have phase transitions between these different topological phases.

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Shengshan Qin, Lunhui Hu, Xianxin Wu, Xia Dai, Chen Fang, Fu-chun Zhang, Jiangping Hu. 2019-01-10. Topological Vortex Phase Transitions in Iron-Based Superconductors. https://doi.org/10.1016/j.scib.2019.07.011

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