General theory of robustness against disorder in multi-band superconductors

Abstract

We investigate the influence of general forms of disorder on the robustness of superconductivity in multiband materials. Specifically, we consider a general two-band system where the bands arise from an orbital degree of freedom of the electrons. Within the Born approximation, we show that the interplay of the spin-orbital structure of the normal-state Hamiltonian, disorder scattering, and superconducting pairing potentials can lead to significant deviations from the expected robustness of the superconductivity. This can be conveniently formulated in terms of the so-called "superconducting fitness". In particular, we verify a key role for unconventional $s$-wave states, permitted by the spin-orbital structure and which may pair electrons that are not time-reversed partners. To exemplify the role of Fermi surface topology and spin-orbital texture, we apply our formalism to the candidate topological superconductor Cu${}_x$Bi${}_2$Se${}_3$, for which only a single band crosses the Fermi energy, as well as models of the iron pnictides, which possess multiple Fermi pockets.

References in corpus (18)

• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• High-temperature superconductivity in iron-based materials
• Magnetism, superconductivity, and pairing symmetry in Fe-based superconductors
• A minimal two-band model for the superconducting Fe-pnictides
• Odd-parity topological superconductor with nematic order: Application to CuxBi2Se3
• Spin fluctuations and superconductivity in a 3D tight-binding model for BaFe2As2
• Superconductivity in three-dimensional spin-orbit coupled semimetals
• Hund interaction, spin-orbit coupling and the mechanism of superconductivity in strongly hole-doped iron pnictides
• Resilient nodeless $d$-wave superconductivity in monolayer FeSe
• Classification of multipole superconductivity in multi-orbital systems and its implications
• Effects of impurities on superconductivity in noncentrosymmetric compounds
• Manifestation of impurity induced s_{+-} -> s_{++} transition: multiband model for dynamical response functions
• Electron irradiation effects on superconductivity in PdTe${}_2$: an application of a generalized Anderson theorem
• Pair breaking due to orbital magnetism in iron-based superconductors
• Origin of the anomalous Hall effect in two-band chiral superconductors
• The effect of interorbital scattering on superconductivity in doped Dirac materials
• Exotic interband pairing in multiband superconductors
• Superconductivity in Cu-doped Bi${}_2$Se${}_3$ with potential disorder

Cited by in corpus (9)

• Using Disorder to Identify Bogoliubov Fermi-Surface States
• Thermoelectric signatures of order-parameter symmetries in iron-based superconducting tunnel junctions
• Inhomogeneous magnetic multiband superconductors
• Bound states around impurities in a superconducting bilayer
• Andreev bound states at nonmagnetic impurities in superconductor/antiferromagnet heterostructures
• Impurity bands in magnetic superconductors with spin density wave
• Circular-polarization-selective perfect reflection from chiral superconductors
• Composite Superconducting Orders and Magnetism in CeRh${}_2$As${}_2$
• Sensitivity of superconducting states to the impurity location in layered materials