Topological Surface States in Paramagnetic and Antiferromagnetic Iron Pnictides

Abstract

The electronic structure of iron pnictides is topologically nontrivial, leading to the appearance of Dirac cones in the band structure for the antiferromagnetic phase. Motivated by the analogy with Dirac cones in graphene, we explore the possible existence of topologically protected surface states. Surprisingly, bands of surface states exist even in the paramagnetic state. A realistic five-orbital model predicts two such bands. In the antiferromagnetic phase, these surface bands survive but split. We obtain the bulk and surface dispersion from exact diagonalization of two- and five-orbital models in a strip geometry and discuss the results based on topology.

5 pages, 4 figures

References in corpus (12)

• The electronic properties of graphene
• Classification of topological insulators and superconductors in three spatial dimensions
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• A minimal two-band model for the superconducting Fe-pnictides
• Edge state on hydrogen-terminated graphite edges investigated by scanning tunneling microscopy
• Time Reversal Invariant Topological Superconductivity and Majorana Kramers Pairs
• Nodal Spin Density Wave and band topology of the FeAs based materials
• Electron and hole Dirac cone states in-pairs in Ba(FeAs)${}_2$ confirmed by magnetoresistance
• ARPES studies of the electronic structure of LaOFe(P,As)
• Magnetic order in orbital models of the iron pnictides
• Role of Dirac cones in magnetotransport properties of REFeAsO (RE=rare earth) oxypnictides

Cited by in corpus (13)

• Classification of reflection symmetry protected topological semimetals and nodal superconductors
• Inflated nodes and surface states in superconducting half-Heusler compounds
• Magnetic interactions in iron superconductors: A review
• Topological Mirror Insulators in One Dimension
• Topological Edge States with Zero Hall Conductivity in a Dimerized Hofstadter Model
• Topological superconductivity and Majorana states in low-dimensional systems
• Spin-orbital interplay and topology in the nematic phase of iron pnictides
• Topological flat bands in optical checkerboard-like lattices
• One-dimensional Dirac electrons on the surface of weak topological insulators
• Topological surface states and Andreev bound states in superconducting iron pnictides
• Semimetallic spin-density wave state in iron pnictides
• Odd-frequency Pairing in the Edge States of Superconducting Pnictides in the Coexistence Phase with Antiferromagnetism
• Weyl semimetallic state with antiferromagnetic order in Rashba-Hubbard model