Statistics of subgap states in $s_{\pm }$ superconductors

Abstract

There is strong support in favor of an unusual $s_{\pm }$ superconducting state in the new iron-based superconductors, in which the gap parameter has opposite signs in different bands. In this case scattering between different bands by impurities has a pair-breaking effect and introduces states inside the gap. We studied the statistics of disorder-induced subgap states in $s_{\pm }$ superconductors due to collective effects of impurities. Numerically solving the two-band Bogolyubov equations, we explored the behavior of the density of states and localization length. We located the mobility edge separating the localized and delocalized states for the 3D case and the crossover between the weak and strong localization regimes for the 2D case. We found that the widely used self-consistent T-matrix approximation is not very accurate in describing subgap states.

7 pages, 5 figures, RevTex 4.1

References in corpus (11)

• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Microwave Surface-Impedance Measurements of the Magnetic Penetration Depth in Single Crystal Ba1-xKxFe2As2 Superconductors: Evidence for a Disorder-Dependent Superfluid Density
• Doping dependence of heat transport in the iron-arsenide superconductor Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$: from isotropic to strongly $k$-dependent gap structure
• Electronic Structure of Fe-Based Superconductors
• Superfluid density and penetration depth in Fe-pnictides
• The London penetration depth in single crystals of Ba(Fe_{1-x}Co_x)_2As_2 at various doping levels
• Non-exponential London penetration depth in Ba${}_{1-}$K${}_x$Fe${}_2$As${}_2$ single crystals
• Impurity Effects in Sign Reversing Fully-Gapped Superconductors: Analysis of FeAs Superconductors
• Impurity-induced in-gap state and Tc in sign-reversing s-wave superconductors: analysis of iron oxypnictide superconductors
• Thermodynamic properties of Ba1-xMxFe2As2 (M = La and K)
• Single Impurity Effects in Multiband Superconductors with Different Sign Order Parameters

Cited by in corpus (14)

• Gap symmetry and structure of Fe-based superconductors
• Charge doping-induced quasiparticle scattering in iron-pnictide superconductors as probed by vortex pinning
• Strong Correlations, Strong Coupling and s-wave Superconductivity in Hole-doped BaFe2As2 Single Crystals
• London penetration depth in Ba(Fe${}_{1-x}$T${}_x$)${}_2$As${}_2$ (T=Co, Ni) superconductors irradiated with heavy ions
• Doping and Irradiation Controlled Vortex Pinning Behavior in BaFe2(As1-xPx)2 Single Crystals
• Anisotropic Phase Diagram and Superconducting Fluctuations in SmFeAsO0.85F0.15
• Anomalous proximity effects at the interface of s and s+- superconductors
• Surface impedance of superconductors with magnetic impurities
• Evolution of London penetration depth with scattering in single crystals of K${}_{1-x}$Na${}_x$Fe${}_2$As${}_2$
• Comparative study of the effects of electron irradiation and natural disorder in single crystals of SrFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ ($x=$0.35) superconductor
• Anisotropic upper critical field of pristine and proton-irradiated single crystals of the magnetically ordered superconductor RbEuFe${}_4$As${}_4$
• Superconducting fluctuations in isovalently-substituted BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$: Possible observation of multiband effects
• Mismatch of conductivity anisotropy in the mixed and normal states of type-II superconductors
• Comment on "Precision global measurements of London penetration depth in FeTe${}_{0.58}$Se${}_{0.42}$"