Quasiparticle Heat Transport in Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$: Evidence for a k-dependent Superconducting Gap without Nodes

Abstract

The thermal conductivity $\kappa$ of the iron-arsenide superconductor Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ ($T_c\simeq$ 30 K) was measured in single crystals at temperatures down to $T\simeq 50$ mK ($\simeq T_c$/600) and in magnetic fields up to $H=15$ T ($\simeq H_{c2}$/4). A negligible residual linear term in $\kappa /T$ as $T\to 0$ shows that there are no zero-energy quasiparticles in the superconducting state. This rules out the existence of line and in-plane point nodes in the superconducting gap, imposing strong constraints on the symmetry of the order parameter. It excludes d-wave symmetry, drawing a clear distinction between these superconductors and the high-$T_c$ cuprates. However, the fact that a magnetic field much smaller than $H_{c2}$ can induce a residual linear term indicates that the gap must be very small on part of the Fermi surface, whether from strong anisotropy or band dependence, or both.

References in corpus (35)

• Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• Nearly Isotropic superconductivity in (Ba,K)Fe2As2
• Superconductivity and Crystal Structures of (Ba1-xKx)Fe2As2 (x = 0 - 1)
• The BCS-like gap in superconductor SmFeAsO_0.85F_0.15
• Impurity-Induced Quasiparticle Transport and Universal Limit Wiedemann-Franz Violation in d-Wave Superconductors
• Electronic thermal conductivity and the Wiedemann-Franz law for unconventional superconductors
• ${}^{75}$As NMR studies of superconducting LaO${}_{0.9}$F${}_{0.1}$FeAs
• Heat Conduction in the Vortex State of NbSe_2: Evidence for Multi-Band Superconductivity
• Momentum dependence of the superconducting gap in NdFeAsO1-xFx single crystals measured by angle resolved photoemission spectroscopy
• Heat Transport in a Strongly Overdoped Cuprate: Fermi Liquid and Pure d-wave BCS Superconductor
• The Fermi surface of Ba(1-x)K(x)Fe2As2 and its evolution with doping
• Thermal Conductivity across the Phase Diagram of Cuprates: Low-Energy Quasiparticles and Doping Dependence of the Superconducting Gap
• Universal Heat Conduction in YBa_2Cu_3O_6.9
• Superconducting gap symmetry of Ba0.6K0.4Fe2As2 studied by angle-resolved photoemission spectroscopy
• Multiple Nodeless Superconducting Gaps in (Ba0.6K0.4)Fe2As2 Superconductor from Angle-Resolved Photoemission Spectroscopy
• Determination of anisotropic Hc2 up to 60 T in (Ba0.55K0.45)Fe2As2 single crystals
• Thermal conductivity of single crystalline MgB_2
• Microwave Surface-Impedance Measurements of the Magnetic Penetration Depth in Single Crystal Ba1-xKxFe2As2 Superconductors: Evidence for a Disorder-Dependent Superfluid Density
• Fully Gapped Superconducting State Based on a High Normal State Quasiparticle Density of States in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Single Crystals
• Low temperature specific heat of the hole-doped Ba_{0.6}K_{0.4}Fe_2As_2 single crystals and electron-doped SmFeAsO_{0.9}F_{0.1} samples
• Unconventional London penetration depth in Ba(Fe0.93Co0.07)2As2 single crystals
• Transport Properties of d-Wave Superconductors in the Vortex State
• Growth and characterization of A_{1-x}K_xFe_2As_2 (A = Ba, Sr) single crystals with x=0 - 0.4
• Magnetic penetration depth of single crystal SmFeAsO_{1-x}F_y: a fully gapped superconducting state
• Non-exponential London penetration depth in RFeAsO${}_{0.9}$F${}_{0.1}$ (R=La,Nd) single crystals
• Heat transport as a probe of superconducting gap structure
• Universal Heat Transport in Sr2RuO4
• Non-exponential London penetration depth in Ba${}_{1-}$K${}_x$Fe${}_2$As${}_2$ single crystals
• Low-temperature phonon thermal conductivity of cuprate single crystals
• Low-temperature magneto-thermal transport investigation of a Ni-based superconductor BaNi2As2: Evidence for fully gapped superconductivity
• Doping dependence of the superconducting gap in Tl_2Ba_2CuO_{6+delta} from heat transport
• Full Gap Superconductivity in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Probed by Muon Spin Rotation
• Orbital fluctuation mechanism for superconductivity in iron-based compounds
• Transport Properties of "Extended-s" State Superconductors

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• Thermal Hall Conductivity as a Probe of Gap Structure in Multi-band Superconductors: The Case of $\mathrm{B}{\mathrm{a}}_{1-\mathrm{x}}{\mathrm{K}}_{\mathrm{x}}\mathrm{F}{\mathrm{e}}_2\mathrm{A}{\mathrm{s}}_2$
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