Decisive proofs of the $s_{\pm }\to s_{++}$ transition in the temperature dependence of the magnetic penetration depth

Abstract

One of the features of the unconventional $s_{\pm }$ state in iron-based superconductors is possibility to transform to the $s_{++}$ state with the increase of the nonmagnetic disorder. Detection of such a transition would prove the existence of the $s_{\pm }$ state. Here we study the temperature dependence of the London magnetic penetration depth within the two-band model for the $s_{\pm }$ and $s_{++}$ superconductors. By solving Eliashberg equations accounting for the spin-fluctuation mediated pairing and nonmagnetic impurities in the $T$-matrix approximation, we have derived a set of specific signatures of the $s_{\pm }\to s_{++}$ transition: (1) sharp change in the behavior of the penetration depth ${\lambda }_L$ as a function of the impurity scattering rate at low temperatures; (2) before the transition, the slope of $\Delta {\lambda }_L(T)={\lambda }_L(T)-{\lambda }_L(0)$ increases as a function of temperature, and after the transition this value decreases; (3) the sharp jump in the inverse square of the penetration depth as a function of the impurity scattering rate, ${\lambda }_L^{-2}({\Gamma }_a)$, at the transition; (4) change from the single-gap behavior in the vicinity of the transition to the two-gap behavior upon increase of the impurity scattering rate in the superfluid density ${\rho }_s(T)$.

arXiv comment8 pages, 6 figures

References in corpus (31)

• Gap symmetry and structure of Fe-based superconductors
• Orbital Fluctuation Mediated Superconductivity in Iron Pnictides: Analysis of Five Orbital Hubbard-Holstein Model
• Violation of Anderson's Theorem for Sign-Reversing s-Wave State of Iron-Pnictide Superconductors
• Effect of magnetic and non-magnetic impurities on highly anisotropic superconductivity
• Self-Consistent Vertex Correction Analysis for Iron-Based Superconductors: Mechanism of Coulomb-Interaction-Driven Orbital Fluctuations
• Using Gap Symmetry and Structure to Reveal the Pairing Mechanism in Fe-based Superconductors
• Superfluid density of the $\pm$s-wave state for the iron-based superconductors
• Resonant impurity scattering in the $\pm$s-gap state of the Fe-based superconductors
• Disorder induced transition between s_+- and s_++ states in two-band superconductors
• Lifting of nodes by disorder in extended-$s$ state superconductors: application to ferropnictides
• Using controlled disorder to distinguish $s_{\pm }$ and $s_{++}$ gap structure in Fe-based superconductors
• Eliashberg approach to superconductivity-induced infrared anomalies in Ba0.68K0.32Fe2As2
• Impurity Effects in Sign Reversing Fully-Gapped Superconductors: Analysis of FeAs Superconductors
• Anisotropic impurities in anisotropic superconductors
• Superconductivity-induced optical anomaly in an iron arsenide
• Sign reversal of the order parameter in s-wave superconductors
• Superconducting state in Fe-based materials and spin-fluctuation theory of pairing
• Impurities in multiband superconductors
• Unexpected impact of magnetic disorder on multiband superconductivity
• Comprehensive Eliashberg analysis of microwave conductivity and penetration depth of K-, Co-, and P-substituted BaFe2As2
• Manifestation of impurity induced s_{+-} -> s_{++} transition: multiband model for dynamical response functions
• Tracing the $s_{\pm }$-symmetry in iron pnictides by controlled disorder
• Analysis of the London penetration depth in Ni-doped CaKFe4As4
• Superconductivity without hole-pocket in electron-doped FeSe: Analysis beyond the Migdal-Eliashberg formalism
• Pair breaking in multi-orbital superconductors: an application to oxide interfaces
• Non-Fermi-Liquid Transport Phenomena and Superconductivity Driven by Orbital Fluctuations in Iron Pnictides: Analysis by Fluctuation-Exchange Approximation
• Non-Fermi-Liquid-Like Behaviors and Superconductivity Driven by Orbital Fluctuations in Iron Pnictides: Analysis by Fluctuation-Exchange Approximation
• Zn-impurity effect and interplay of $s_{\pm }$- and $s_{++}$-pairings in Fe-based superconductors
• Disorder effects in multiorbital $s_{\pm }$-wave superconductors: Implications for Zn-doped BaFe${}_2$As${}_2$ compounds
• Details of the disorder-induced transition between $s_{\pm }$ and $s_{++}$ states in two-band model for Fe-based superconductors
• Temperature-dependent $s_{\pm }\leftrightarrow s_{++}$ transitions in the multiband model for Fe-based superconductors with impurities

Cited by in corpus (2)

• Thermodynamics of $s_{\pm }-to-s_{++}$ transition in iron pnictides in the vicinity of the Born limit
• Critical point of the transition between $s_{\pm }$ and $s_{++}$ states of a two-band superconductor with nonmagnetic impurities