Superconducting gap symmetry of Ba0.6K0.4Fe2As2 studied by angle-resolved photoemission spectroscopy

Abstract

We have performed high-resolution angle-resolved photoemission spectroscopy on the optimally-doped Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ compound and determined the accurate momentum dependence of the superconducting (SC) gap in four Fermi-surface sheets including a newly discovered outer electron pocket at the M point. The SC gap on this pocket is nearly isotropic and its magnitude is comparable ($\Delta$ $\sim$ 11 meV) to that of the inner electron and hole pockets ($\sim$12 meV), although it is substantially larger than that of the outer hole pocket ($\sim$6 meV). The Fermi-surface dependence of the SC gap value is basically consistent with $\Delta$($k$) = $\Delta$${}_0$cos$k_x$cos$k_y$ formula expected for the extended s-wave symmetry. The observed finite deviation from the simple formula suggests the importance of multi-orbital effects.

arXiv comment4 pages, 3 figures, 1 table

References in corpus (15)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Destruction of the Fermi Surface in Underdoped High Tc Superconductors
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• Funtional Renormalization Group Study of the Pairing Symmetry and Pairing Mechanism of the FeAs Based High Temperature Superconductors
• A Numerical Renormalization Group Study of the Superconducting and Spin Density Wave Instabilities in MFeAsO${}_{1-x}$F${}_x$ Compounds
• Pairing Symmetry in a Two-Orbital Exchange Coupling Model of Oxypnictides
• The BCS-like gap in superconductor SmFeAsO_0.85F_0.15
• Theory of magnetic excitations in iron-based layered superconductors
• The Fermi surface of Ba(1-x)K(x)Fe2As2 and its evolution with doping
• Multiple Nodeless Superconducting Gaps in (Ba0.6K0.4)Fe2As2 Superconductor from Angle-Resolved Photoemission Spectroscopy
• Transport and anisotropy in single-crystalline SrFe${}_2$As${}_2$ and $A_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ ($A$ = Sr, Ba) superconductors
• Electron-hole Asymmetry and Quantum Critical Point in Hole-doped BaFe${}_2$As${}_2$

Cited by in corpus (142)

• The Puzzle of High Temperature Superconductivity in Layered Iron Pnictides and Chalcogenides
• Gap symmetry and structure of Fe-based superconductors
• Pnictogen height as a possible switch between high-T_c nodeless and low-T_c nodal pairings in the iron based superconductors
• Iron-Based Superconductors: current status of materials and pairing mechanism
• Pairing Symmetry and Pairing State in Ferropnictides: Theoretical Overview
• Fermi surface nesting induced strong pairing in iron-based superconductors
• Violation of Anderson's Theorem for Sign-Reversing s-Wave State of Iron-Pnictide Superconductors
• Three-band superconductivity and the order parameter that breaks time-reversal symmetry
• Spin fluctuations and superconductivity in a 3D tight-binding model for BaFe2As2
• Band Structure and Fermi Surface of an Extremely Overdoped Iron-Based Superconductor KFe2As2
• Three orbital model for the iron-based superconductors
• Unconventional Anisotropic s-Wave Superconducting Gaps of LiFeAs Iron-Pnictide Superconductor
• Phase diagram and Gap anisotropy in Iron-Pnictide Superconductors
• Fe-based superconductors: an angle-resolved photoemission spectroscopy perspective
• Nodes in the gap structure of the iron-arsenide superconductor Ba(Fe_{1-x}Co_x)_2As_2 from c-axis heat transport measurements
• 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
• Sensitivity of the superconducting state and magnetic susceptibility to key aspects of electronic structure in ferropnictides
• Momentum dependence and nodes of the superconducting gap in iron-pnictides
• Strong nodeless pairing on separate electron Fermi surface sheets in (Tl, K)Fe${}_{1.78}$Se${}_2$ probed by ARPES
• Isotropic superconducting gaps with enhanced pairing on electron Fermi surfaces in FeTe0.55Se0.45
• Antiferromagnetically Driven Electronic Correlation in Iron Pnictides and Cuprates
• Possible Multiple Gap Superconductivity with Line Nodes in Heavily Hole-Doped Superconductor KFe2As2 Studied by 75As-NQR and Specific Heat
• Structure of Neutron-Scattering Peak in both s++ wave and s+- wave states of an Iron pnictide Superconductor
• Angle-resolved photoemission spectroscopy
• Local antiferromagnetic exchange and collaborative Fermi surface as key ingredients of high temperature superconductors
• Recent progress on superconductors with time-reversal symmetry breaking
• Pauli-limiting effects in the upper critical fields of a clean LiFeAs single crystal
• Superfluid density and penetration depth in Fe-pnictides
• Crossover from weak to strong pairing in unconventional superconductors
• Magnetic Resonant Mode in the Low-Energy Spin-Excitation Spectrum of Superconducting Rb2Fe4Se5 Single Crystals
• Quasiparticle Heat Transport in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$: Evidence for a k-dependent Superconducting Gap without Nodes
• Directional point-contact Andreev-reflection spectroscopy of Fe-based superconductors: Fermi surface topology, gap symmetry, and electron-boson interaction
• Electronic structure of optimally doped pnictide Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$: a comprehensive ARPES investigation
• Universality of superconducting gaps in overdoped Ba0.3K0.7Fe2As2 observed by angle-resolved photoemission spectroscopy
• Possible nodal superconducting gap emerging at the Lifshitz transition in heavily hole-doped Ba0.1K0.9Fe2As2
• Dependence of carrier doping on the impurity potential in transition-metal-substituted FeAs-based superconductors
• Superconductivity suppression of Ba0.5K0.5Fe2-2xM2xAs2 single crystals by substitution of transition-metal (M = Mn, Ru, Co, Ni, Cu, and Zn)
• Fermi surface dichotomy of the superconducting gap and pseudogap in underdoped pnictides
• Non-exponential London penetration depth in Ba${}_{1-}$K${}_x$Fe${}_2$As${}_2$ single crystals
• Unconventional superconducting gap in NaFe${}_{0.95}$Co${}_{0.05}$As observed by angle-resolved photoemission spectroscopy
• Nonmagnetic Impurity Resonances as a Signature of Sign-Reversal Pairing in the FeAs-based Superconductors
• Electron-Hole Asymmetry in Superconductivity of Pnictides Originated from the Observed Rigid Chemical Potential Shift
• Point contact Andreev reflection spectroscopy of superconducting energy gaps in 122-type family of iron pnictides
• Superconducting Properties of the $s^{\pm }$-wave state: Fe-based superconductors
• Impurity-induced bound states in iron-based superconductors with s-wave cos(kx)cos(ky) pairing symmetry
• $S_4$ Symmetric Microscopic Model for Iron-Based Superconductors
• Large decrease in the critical temperature of superconducting LaFeAsO0.85 compounds doped with 3% atomic weight of nonmagnetic Zn impurities
• Orbital Characters Determined from Fermi Surface Intensity Patterns using Angle-Resolved Photoemission Spectroscopy
• Three-dimensional electronic structure of superconducting iron pnictides observed by angle-resolved photoemission spectroscopy
• Optical conductivity of Ba0.6 K0.4 Fe2 As2 : The effect of in-plane and out-of-plane doping in the superconducting gap
• Universal behavior of the upper critical field in iron based superconductors
• Three-dimensional nodal superconducting gap in single crystals Ba(Fe${}_{1-x}$Ni${}_x$)${}_2$As${}_2$
• Quasiparticle Scattering Interference in Superconducting Iron-pnictides
• Linear decrease of critical temperature with increasing Zn substitution in the iron-based superconductor BaFe1.89-2xZn2xCo0.11As2
• Neutron-Inelastic-Scattering Peak by Dissipationless Mechanism in the s++ -wave State in Iron-based Superconductors
• A balancing act: Evidence for a strong subdominant d-wave pairing channel in $\mathrm{B}{\mathrm{a}}_{0.6}{\mathrm{K}}_{0.4}\mathrm{F}{\mathrm{e}}_2\mathrm{A}{\mathrm{s}}_2$
• Optical and Raman spectroscopy studies on Fe-based superconductors
• Evidence for exclusion of the possibility of $d$-wave superconducting-gap symmetry in Ba-doped KFe${}_2$As${}_2$
• Odd and even modes of neutron spin resonance in the bilayer iron-based superconductor CaKFe${}_4$As${}_4$
• High-temperature superconductivity stabilized by electron-hole interband coupling in collapsed tetragonal phase of KFe2As2 under high pressure
• Spectral properties of transition metal pnictides and chalcogenides: angle-resolved photoemission spectroscopy and dynamical mean field theory
• Superconductivity without Fe or Ni in the phosphides BaIr2P2 and BaRh2P2
• ARPES measurements of the superconducting gap of Fe-based superconductors and their implications to the pairing mechanism
• Theory of thermal conductivity in extended-$s$ state superconductors: application to ferropnictides
• Observation of an isotropic superconducting gap at the Brillouin zone center of Tl${}_{0.63}$K${}_{0.37}$Fe${}_{1.78}$Se${}_2$
• A brief review on muSR studies of unconventional Fe and Cr-based superconductors
• Probing the pairing symmetry of the iron pnictides with electronic Raman scattering
• Spin-Density-Wave and Asymmetry of Coherence Peaks in iron-Pnictide Superconductors from a two-orbital model
• Unconventional density waves and superconductivities in Fe-based superconductors and other strongly correlated electron systems
• Magnetic Properties of the Superconducting State of Iron-Based Superconductors
• High Pressure Synthesis of Indirectly electron-doped 122 Iron Superconductor Sr1-xLaxFe2As2 with a maximum Tc = 22 K
• Precision Microwave Electrodynamic Measurements of K- and Co-doped BaFe${}_2$As${}_2$
• Nodeless superconducting gap in electron-doped BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$ probed by quasiparticle heat transport
• Point-contact spectroscopic studies on normal and superconducting AFe_2As_2-type iron-pnictide single crystals
• Nodes in the Order Parameter of Superconducting Iron Pnictides Observed by Infrared Spectroscopy
• Josephson Effects in Three-Band Superconductors with Broken Time-Reversal Symmetry
• Evidence of a universal and isotropic 2Δ/kBTC ratio in 122-type iron pnictide superconductors over a wide doping range
• Superconductivity and electronic fluctuations in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ studied by Raman scattering
• Nodes vs. minima in the energy gap of iron-pnictides from field-induced anisotropy
• Angle-resolved photoemission spectroscopy study of PrFeAsO_{0.7}: Dependence of the electronic structure on the pnictogen height
• Superconducting phase fluctuations in SmFeAsO${}_{0.8}$F${}_{0.2}$ from diamagnetism at low magnetic field above $T_c$
• Anomalous proximity effects at the interface of s and s+- superconductors
• Thermal conductivity of overdoped BaFe${}_{1.73}$Co${}_{0.27}$As${}_2$ single crystal: Evidence for nodeless multiple superconducting gaps and interband interactions
• Magnetic penetration-depth measurements of a suppressed superfluid density of superconducting Ca${}_{0.5}$Na${}_{0.5}$Fe${}_2$As${}_2$ single crystals by proton irradiation
• Paraconductivity of K-doped SrFe2As2 superconductor
• Multiband strong-coupling superconductors with spontaneously broken time-reversal symmetry
• Theory of tunnelling into a multi-band superconductor: decoherence and interference
• Microwave conductivity in the ferropnictides with specific application to Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$
• Progress in nonmagnetic impurity doping studies on Fe-based superconductors
• Proximity fingerprint of s+- superconductivity
• Topological magnetic order and superconductivity in EuRbFe${}_4$As${}_4$
• Quasi-Two-Dimensional Fermi Surfaces and Coherent Interlayer Transport in KFe${}_2$As${}_2$
• Structural and superconducting properties in LaFeAs1-xSbxO1-yFy
• Spin dynamics in electron-doped pnictide superconductors
• Determination of the pairing state in iron-based superconductors through neutron scattering
• Robust accidental nodes and zeroes and critical quasiparticle scaling in iron-based multiband superconductors
• Orbital-Selective Superconductivity and the Effect of Lattice Distortion in Iron-Based Superconductors
• Green function theory of dirty two-band superconductivity
• NMR investigation of vortex dynamics in Ba(Fe0.93Rh0.07)2As2 superconductor
• Electronic dispersion anomalies in the iron pnictide superconductor Ba_{1-x}K_xFe_2As_2
• Optical properties of the optimally doped Ca${}_{8.5}$La${}_{1.5}$(Pt${}_3$As${}_8$)(Fe${}_2$As${}_2$)${}_5$ single crystal
• Infrared probe of the gap evolution across the phase diagram of Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$
• ARPES observation of isotropic superconducting gaps in isovalent Ru-substituted Ba(Fe${}_{0.75}$Ru${}_{0.25}$)${}_2$As${}_2$
• A Unified Description of Cuprate and Iron Arsenide Superconductors
• Quasiparticle Interference in Fe-based Superconductors Based on a Five-Orbital Tight-Binding Model
• Orbitally resolved lifetimes in Ba(Fe0.92Co0.08)2As2 measured by ARPES
• Genuine Electronic Structure and Superconducting Gap Structure in (Ba${}_{0.6}$K${}_{0.4}$)Fe${}_2$As${}_2$ Superconductor
• Opening of the superconducting gap in the hole pockets of Ba(Fe(1-x)Co(x))2As2 as seen via Angle-Resolved PhotoElectron Spectroscopy
• Constraints Imposed by Symmetry on Pairing Operators for the Pnictides
• In-gap Bound States Induced by Interstitial Fe Impurities in Iron-based Superconductors
• Two-Gap Superconductivity in CaFe_{0.88}Co_{0.12}AsF Revealed by Temperature Dependence of the Lower Critical Field H_{c1}^c(T)
• Many-body physics-induced selection rules: application to Raman spectroscopy
• The effect of disorder on electronic Raman scattering in the superconducting state of iron pnictides
• The effect of spin fluctuations on the electronic structure in iron based superconductors
• Theory of Mixed-State Effect on Quasiparticle Interference in Iron-based Superconductors
• Comment on "Isoelectronic Ru substitution at Fe-site in Sm(Fe${}_{1-x}$Ru${}_x$)AsO${}_{0.85}$F${}_{0.15}$ compound and its effects on structural, superconducting and normal state properties" (arXiv:1004.1978)
• Evolution of quasiparticle states with and without a Zn-impurity in doped 122 iron pnictides
• Q-scan-analysis of the neutron scattering in iron-based superconductors
• Angle-resolved photoemission studies of the superconducting gap symmetry in Fe-based superconductors
• Orbital Compass Model as an Itinerant Electron System
• Collective Mode at Lifshitz Transition in Iron-Pnictide Superconductors
• Revealing the intrinsic superconducting gap anisotropy in surface-neutralized BaFe${}_2$(As${}_{0.7}$P${}_{0.3}$)${}_2$
• Ultrafast quasiparticle dynamics in superconducting iron pnictide CaFe1.89Co0.11As2
• Gap-dependent quasiparticle dynamics and coherent acoustic phonons in parent iron pnictide CaFe2As2 across the spin density wave phase transition
• Superconducting Gaps via Raman Scattering in Iron Superconductors
• Deviating band symmetries and many-body interactions in a model hole doped iron pnictide superconductor
• In-plane magnetic field vs. temperature phase diagram of a quasi-2D frustrated multiband superconductor
• Orbital-dependent modulation of the superconducting gap in uniaxially strained Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$
• Isotropic multi-gap superconductivity in BaFe1.9Pt0.1As2 from thermal transport and spectroscopic measurements
• Superconducting Gap and Symmetry in FeSe_1-x_Te_x_ Studied by Specific Heat in Magnetic Fields
• Hybrid Crystals of Cuprates and Iron-Based Superconductors
• Proximity effect and inverse proximity effect in a topological-insulator/iron-based-superconductor heterostructure
• Coherence effect in a two-band superconductor: Application to iron pnictides
• Evolution of superconducting gap anisotropy in hole-doped 122 iron pnictides
• First-principles-based $\pm s$-wave modelling for iron-based superconductors:Studies for specific heat and nuclear magnetic relaxation rate
• The Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ superconducting four-gap temperature evolution: a multi-band Chebyshev-BdG approach
• A Short Review of the $S_4$ Symmetric Microscopic Model for Iron-Based High Temperature Superconductors
• Strong spin resonance on BaFe2(As0.65P0.35)2 with Tc = 30 K
• Experimentally Realized Correlated Electron Materials: From Superconductors to Topological Insulators
• Zero Energy Bound States on Nano Atomic Line Defect in Iron-based High Temperature Superconductors
• Nesting-induced Local Electronic Patterns around a Single As (Te, Se) Vacancy in Iron-based Superconductors
• Observation of a ubiquitous three-dimensional superconducting gap function in optimally-doped Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$