From d-wave to s-wave pairing in the iron-pnictide superconductor (Ba,K)Fe2As2

Abstract

The nature of the pairing state in iron-based superconductors is the subject of much debate. Here we argue that in one material, the stoichiometric iron pnictide KFe2As2, there is overwhelming evidence for a d-wave pairing state, characterized by symmetry-imposed vertical line nodes in the superconducting gap. This evidence is reviewed, with a focus on thermal conductivity and the strong impact of impurity scattering on the critical temperature Tc. We then compare KFe2As2 to Ba0.6K0.4Fe2As2, obtained by Ba substitution, where the pairing symmetry is s-wave and the Tc is ten times higher. The transition from d-wave to s-wave within the same crystal structure provides a rare opportunity to investigate the connection between band structure and pairing mechanism. We also compare KFe2As2 to the nodal iron-based superconductor LaFePO, for which the pairing symmetry is probably not d-wave, but more likely s-wave with accidental line nodes.

References in corpus (11)

• Nearly Isotropic superconductivity in (Ba,K)Fe2As2
• Evidence for nodal superconductivity in LaFePO
• Determination of anisotropic Hc2 up to 60 T in (Ba0.55K0.45)Fe2As2 single crystals
• Magnetoelastic Coupling in the Phase Diagram of Ba1-xKxFe2As2
• Resistivity and upper critical field in KFe${}_2$As${}_2$ single crystals
• Nodes in the Gap Function of LaFePO, the Gap Function of the Fe(Se,Te) Systems, and the STM Signature of the s${}_{\pm }$ Pairing
• From d-wave to s-wave pairing in the iron-pnictide superconductor (Ba,K)Fe2As2
• Electron-hole Asymmetry and Quantum Critical Point in Hole-doped BaFe${}_2$As${}_2$
• Universal pair-breaking in transition metal-substituted iron-pnictide superconductors
• Anomalous impurity effects in the iron-based superconductor KFe${}_2$As${}_2$
• Orbital-dependent electron correlation effect on the two- and three-dimensional Fermi surfaces in KFe2As2 revealed by angle-resolved photoemission spectroscopy

Cited by in corpus (46)

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• Vertical line nodes in the superconducting gap structure of Sr2RuO4
• Thermodynamic evidence for the Fulde-Ferrell-Larkin-Ovchinnikov state in the KFe2As2 superconductor
• Strong Correlations, Strong Coupling and s-wave Superconductivity in Hole-doped BaFe2As2 Single Crystals
• Energy Gap Evolution Across the Superconductivity Dome in Single Crystals of (Ba${}_{1-x}$K${}_x$)Fe${}_2$As${}_2$
• From d-wave to s-wave pairing in the iron-pnictide superconductor (Ba,K)Fe2As2
• A comprehensive scenario of the single crystal growth and doping dependence of resistivity and anisotropic upper critical fields in (Ba${}_{1-x}$K${}_x$)Fe${}_2$As${}_2$ ($0.22\le x\le 1$)
• Nematic superconducting state in iron pnictide superconductors
• Sign inversion in the superconducting order parameter of LiFeAs inferred from Bogoliubov quasiparticle interference
• Universal V-shaped temperature-pressure phase diagram in the iron-based superconductors KFe2As2, RbFe2As2, and CsFe2As2
• Distinguishing between $s+id$ and $s+is$ pairing symmetries in multiband superconductors through spontaneous magnetization pattern induced by a defect
• Effects of electron irradiation on resistivity and London penetration depth of Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ ($x\le$ 0.34) iron - pnictide superconductor
• Evidence of d-wave Superconductivity in K_(1-x)Na_xFe_2As_2 (x = 0, 0.1) Single Crystals from Low-Temperature Specific Heat Measurements
• Multiband Superconductivity in KFe2As2: Evidence for one Isotropic and several Liliputian Energy Gaps
• Heat capacity jump at Tc and pressure derivatives of superconducting transition temperature in the Ba1-xKxFe2As2 (0.2 < x < 1.0) series
• Thermoelectric Signatures of Time-Reversal Symmetry Breaking States in Multiband Superconductors
• A brief review on muSR studies of unconventional Fe and Cr-based superconductors
• Microscopically derived multi-component Ginzburg-Landau theories for $s+is$ superconducting state
• Competition between superconductivity and magnetic/nematic order as a source of anisotropic superconducting gap in underdoped Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$
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• High-Temperature Majorana Fermions in Magnet-Superconductor Hybrid Systems
• Evolution of London penetration depth with scattering in single crystals of K${}_{1-x}$Na${}_x$Fe${}_2$As${}_2$
• Doping evolution of the superconducting gap structure in the underdoped iron arsenide Ba1-xKxFe2As2 revealed by thermal conductivity
• Improper s-wave symmetry for the electronic pairing in iron-based superconductors by first-principles calculation
• Nodal superconductivity in isovalently substituted SrFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$ pnictide superconductor at the optimal doping, $x=$0.35
• Probing the pairing symmetry in the over-doped Fe-based superconductor Ba_0.35Rb_0.65Fe_2As_2 as a function of hydrostatic pressure
• Effect of heavy-ion irradiation on London penetration depth in over-doped Ba(Fe,Co)2As2
• Unconventional bulk superconductivity in YFe${}_2$Ge${}_2$ single crystals
• Dielectric Resonator Method For Determining Gap Symmetry Of Superconductors Through Anisotropic Nonlinear Meissner Effect
• Multiband thermal transport in the iron-based superconductor Ba1 xKxFe2As2
• Point contact spectroscopy in Fe-based superconductors: recent advancements and future challenges
• Observation of a crossover from nodal to gapped superconductivity in Lu${}_x$Zr${}_{1-x}$B${}_{12}$
• Specific Heat Investigation for Line Nodes in Heavily Overdoped Ba1-xKxFe2As2
• Orbital and Pauli limiting effects in heavily doped Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$
• Single 20meV boson mode in KFe2As2 detected by point-contact spectroscopy
• Isotropic multi-gap superconductivity in BaFe1.9Pt0.1As2 from thermal transport and spectroscopic measurements
• Superconductivity In K- And Na- Doped Bafe2as2: What Can We Learn From Heat Capacity And Pressure Dependence of Tc
• Evidence for nodal superconductivity in a layered compound Ta${}_4$Pd${}_3$Te${}_{16}$
• Evolution of superconducting gap anisotropy in hole-doped 122 iron pnictides
• Impact of Disorder on the Superconducting Properties and BCS-BEC Crossover in FeSe Single Crystals
• Thermodynamics of $s_{\pm }-to-s_{++}$ transition in iron pnictides in the vicinity of the Born limit
• Orbital driven two-dome superconducting phases in multiorbital superconductors
• Thermal Hall conductivity in the strongest cuprate superconductor: Estimate of the mean free path in the trilayer cuprate HgBa${}_2$Ca${}_2$Cu${}_3$O${}_{8+\delta }$