Topological surface states and Andreev bound states in superconducting iron pnictides

Abstract

The nontrivial topology of the electronic structure of iron pnictides can lead to the appearance of surface states. We study such states in various strip geometries with a focus on the superconducting phase. In the presence of unconventional superconducting pairing with $s_{\pm }$-wave gap structure, the topological states are quite robust and partly remain in the superconducting gap. Furthermore, Andreev bound states appear, which coexist with the topological states for small superconducting gaps and merge with them for larger gap values. The bulk and surface dispersions are obtained from exact diagonalization for two-orbital and five-orbital models in strip geometries.

9 pages, 11 figures

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Cited by in corpus (4)

• Inflated nodes and surface states in superconducting half-Heusler compounds
• Topological superconductivity and Majorana states in low-dimensional systems
• One-dimensional Dirac electrons on the surface of weak topological insulators
• Linear scaling relation between two-dimensional massless Dirac fermion Fermi velocity and Fe-As bond length in iron arsenide superconductor systems