Topological states in A15 superconductors

Abstract

Superconductors with the A15 structure are prototypical type-II s-wave superconductors which have generated considerable interest in early superconducting material history. However, the topological nature of the electronic structure remains unnoticed so far. Here, using first-principles band structure calculations based on density functional theory, we show that the A15 superconductors (Ta${}_3$Sb, Ta${}_3$Sn, and Ta${}_3$Pb) have nontrivial band topology in the bulk electronic band structures, leading to the formation of topological surface states near the Fermi energy. Due to the bulk superconductivity, the proximity effect in the topological surface states would induce topological superconductivity even without heterostructure of a topological insulator and an s-wave superconductor. Our results indicate that the A15 superconductors are promising candidates for the realization of the topological superconductivity and the Majorana fermion.

arXiv comment11 pages, 4 figures

References in corpus (25)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Topological Insulators
• Topological insulators and superconductors
• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Insulators in Three Dimensions
• Topological Insulators with Inversion Symmetry
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
• Helical liquids and Majorana bound states in quantum wires
• A generic new platform for topological quantum computation using semiconductor heterostructures
• Majorana fermions in a tunable semiconductor device
• Observation of topological superconductivity on the surface of an iron-based superconductor
• Unconventional superconductivity on a topological insulator
• Recent advances in iron-based superconductors toward applications
• First Principles Studies on 3-Dimentional Strong Topological Insulators: Bi2Te3, Bi2Se3 and Sb2Te3
• Topological nature of FeSe${}_{0.5}$Te${}_{0.5}$ superconductor
• Topological superconductivity on the surface of Fe-based superconductors
• A large energy-gap oxide topological insulator based on the superconductor BaBiO3
• Superconducting Topological Surface States in Non-centrosymmetric Bulk Superconductor PbTaSe2
• Majorana bound states without vortices in topological superconductors with electrostatic defects
• Fermion zero modes at the boundary of superfluid 3He-B
• Strongly enhanced Rashba splittings in oxide heterostructure: a tantalite monolayer on BaHfO${}_3$

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