Non-magnetic impurity effects in a three-dimensional topological superconductor: From p- to s-wave behaviors

Abstract

Unconventional features in superconductivity are revealed by responses to impurity scattering. We study non-magnetic impurity effects in a three-dimensional topological superconductor, focusing on an effective model (massive Dirac Hamiltonian with s-wave on-site pairing) of Copper-doped bismuth-selenium compounds. Using a self-consistent T-matrix approach for impurity scattering, we examine in-gap states in density of states. We find that the results are well characterized by a single material variable, which measures relativistic effects in the Dirac Hamiltonian. In non-relativistic regime, an odd-parity superconducting state is fragile against non-magnetic impurities. We show that this behavior is caused by a p-wave character involved in the topological superconducting state. In contrast, we show that in relativistic regime the superconductivity is robust against non-magnetic impurities, owing to an s-wave character. To summarize, the system has two aspects, p- and s-wave features, depending on the weight of relativistic effects.

7 pages, 4 figures, final version

References in corpus (5)

• Topological Insulators with Inversion Symmetry
• Classification of topological insulators and superconductors in three spatial dimensions
• Non-Abelian Topological Orders and Majorana Fermions in Spin-Singlet Superconductors
• Local Measurements of the Superconducting Pairing Symmetry in CuxBi2Se3
• Surface spectral function in the superconducting state of a topological insulator

Cited by in corpus (6)

• Impurity-induced bound states in superconductors with spin-orbit coupling
• Superconducting doped topological materials
• Non-fragile superconductivity with nodes in the superconducting topological insulator CuxBi2Se3: Zeeman orbital field and non-magnetic impurities
• Topological s-wave pairing superconductivity with spatial inhomogeneity: Mid-gap-state appearance and robustness of superconductivity
• Possible two-component pairings in electron-doped Bi${}_2$Se${}_3$ based on a tight-binding model
• Layer-Resolved Impurity States Reveal Competing Pairing Mechanisms in Trilayer Nickelate Superconductor La${}_4$Ni${}_3$O${}_{10}$