CaFeAs${}_2$: a Staggered Intercalation of Quantum Spin Hall and High Temperature Superconductivity

Abstract

We predict that CaFeAs${}_2$, a newly discovered iron-based high temperature (T${}_c$) superconductor, is a staggered intercalation compound that integrates topological quantum spin hall (QSH) and superconductivity (SC). CaFeAs${}_2$ has a structure with staggered CaAs and FeAs layers. While the FeAs layers are known to be responsible for high T${}_c$ superconductivity, we show that with spin orbital coupling each CaAs layer is a $Z_2$ topologically nontrivial two-dimensional QSH insulator and the bulk is a 3-dimensional weak topological insulator. In the superconducting state, the edge states in the CaAs layer are natural 1D topological superconductors. The staggered intercalation of QSH and SC provides us an unique opportunity to realize and explore novel physics, such as Majorana modes and Majorana Fermions chains.

4.5 pages, 5 figures + supplemental material,published version

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Cited by in corpus (6)

• Exploring Topological Superconductivity in Topological Materials
• Discovery of a novel 112-type iron-pnictide and La-doping induced superconductivity in Eu1-xLaxFeAs2 (x = 0 ~ 0.15)
• Observation of the anisotropic Dirac cone in the band dispersion of 112-structured iron-based superconductor Ca0.9La0.1FeAs2
• Phase stability and large in-plane resistivity in the 112-type iron-based superconductor Ca${}_{1-x}$La${}_x$FeAs${}_2$
• Quasi-2D behavior of 112-type iron-based superconductors
• Site-Selective Antimony Doping in Arsenic Zigzag Chains of 112-type Ca1-xLaxFeAs2