Topological Superconductivity on the Surface of Fe-Based Superconductors

Gang Xu, Biao Lian, Peizhe Tang, Xiao Liang Qi, Shou Cheng Zhang

Research output: Contribution to journalArticlepeer-review

Abstract

As one of the simplest systems for realizing Majorana fermions, the topological superconductor plays an important role in both condensed matter physics and quantum computations. Based on ab initio calculations and the analysis of an effective 8-band model with superconducting pairing, we demonstrate that the three-dimensional extended s-wave Fe-based superconductors such as Fe1+ySe0.5Te0.5 have a metallic topologically nontrivial band structure, and exhibit a normal-topological-normal superconductivity phase transition on the (001) surface by tuning the bulk carrier doping level. In the topological superconductivity (TSC) phase, a Majorana zero mode is trapped at the end of a magnetic vortex line. We further show that the surface TSC phase only exists up to a certain bulk pairing gap, and there is a normal-topological phase transition driven by the temperature, which has not been discussed before. These results pave an effective way to realize the TSC and Majorana fermions in a large class of superconductors.

Original languageEnglish (US)
Article number047001
JournalPhysical review letters
Volume117
Issue number4
DOIs
StatePublished - Jul 18 2016
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Topological Superconductivity on the Surface of Fe-Based Superconductors'. Together they form a unique fingerprint.

Cite this