Point-Contact Spectroscopy of Iron-Based Layered Superconductor LaO${}_{0.9}$F${}_{0.1-\delta }$FeAs

Abstract

We present point-contact spectroscopy data for junctions between a normal metal and the newly discovered F-doped superconductor LaO${}_{0.9}$F${}_{0.1-\delta }$FeAs (F-LaOFeAs). A zero-bias conductance peak was observed and its shape and magnitude suggests the presence of Andreev bound states at the surface of F-LaOFeAs, which provides a possible evidence of an unconventional pairing symmetry with a nodal gap function. The maximum gap value ${\Delta }_0\approx 3.9\pm 0.7$meV was determined from the measured spectra, in good agreement with the recent experiments on specific heat and lower critical field.

5 pages, 4 figures

References in corpus (16)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• 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
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Is LaO${}_{1-x}$F${}_x$FeAs an electron-phonon superconductor ?
• Superconductivity at 25 K in hole doped $(L{a}_{1-x}S{r}_x)OFeAs$
• Superconductivity at 52 K in iron-based F-doped layered quaternary compound Pr[O1-xFx]FeAs
• Proximity of antiferromagnetism and superconductivity in LaO${}_{1-x}$F${}_x$FeAs: effective Hamiltonian from ab initio studies
• Electron Correlations in the Low Carrier Density LaFeAsO0.89F0.11 Superconductor (Tc = 28 K)
• Spin-singlet superconductivity with multiple gaps in PrO0.89F0.11FeAs
• The role of critical current on point contact Andreev Reflection spectrum between a normal metal and a superconductor
• Hall effect and magnetoresistance in the normal state of the superconductor LaO${}_{0.9}$F${}_{0.1-x}$FeAs
• Upper critical field, Hall effect and magnetoresistance in the iron-based layered superconductor LaFeAsO_{0.9}F_{0.1-δ}
• Superconducting properties of Fe-based layered superconductor LaO${}_{0.9}$F${}_{0.1-\delta }$FeAs
• Even Parity, Orbital Singlet and Spin Triplet Pairing for Superconducting $La(O_{1-x}{F}_x)FeAs$
• Linear Temperature Dependence of the Lower Critical Field $H_{c1}$ in F-Doped LaOFeAs Superconductors

Cited by in corpus (50)

• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Funtional Renormalization Group Study of the Pairing Symmetry and Pairing Mechanism of the FeAs Based High Temperature Superconductors
• Pairing Symmetry in a Two-Orbital Exchange Coupling Model of Oxypnictides
• The BCS-like gap in superconductor SmFeAsO_0.85F_0.15
• Microwave Penetration Depth and Quasiparticle Conductivity in PrFeAsO_1-y Single Crystals : Evidence for a Full-Gap Superconductor
• 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
• Spin Fluctuations, Interband Coupling, and Unconventional Pairing in Iron-based Superconductors
• Upper critical field, anisotropy, and superconducting properties of Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ single crystals
• Superfluid density of the $\pm$s-wave state for the iron-based superconductors
• Superconductivity coexisting with phase-separated static magnetic order in (Ba,K)Fe${}_2$As${}_2$, (Sr,Na)Fe${}_2$As${}_2$ and CaFe${}_2$As${}_2$
• Lifting of nodes by disorder in extended-$s$ state superconductors: application to ferropnictides
• Evidence for Two Gaps and Breakdown of the Uemura Plot in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Single Crystals
• Properties of a two orbital model for oxypnictide superconductors: Magnetic order, B_2g spin-singlet pairing channel, and its nodal structure
• Intrinsic Properties of Stoichiometric LaOFeP
• Crossover from weak to strong pairing in unconventional superconductors
• Possible pairing states of the Fe-based superconductors
• Observation of the Josephson effect in Pb/(Ba,K)Fe2As2 single crystal junctions
• Muon spin relaxation studies of magnetic order and superfluid density in antiferromagnetic NdOFeAs, BaFe2As2 and superconducting (Ba,K)Fe2As2
• Hall effect and magnetoresistance in single crystals of NdFeAsO${}_{1-x}$F${}_x$
• Neutron and ARPES Constraints on the Couplings of the Multiorbital Hubbard Model for the Pnictides
• Scanning tunneling spectroscopy of SmFeAsO0.85: Possible evidence for d-wave order parameter symmetry
• Nodal Superconductivity with Multiple Gaps in SmFeAsO${}_{0.9}$F${}_{0.1}$
• Magnetization Relaxation and Collective Vortex Pinning in the Fe-Based Superconductor SmFeAsO_0.9F_0.1
• Normal State Correlated Electronic Structure of Iron Pnictides
• Spin excitations in the excitonic spin-density-wave state of the iron pnictides
• Possible two-gap superconductivity in NdFeAs(O,F) probed by point-contact Andreev-reflection spectroscopy
• Coexistence of two order parameters and a pseudogaplike feature in the iron-based superconductor LaFeAsO_(1-x)F_x
• On the electronic structure of electron doped LaOFeAs as seen by X-ray absorption spectroscopy
• Anisotropy of superconducting single crystal SmFeAsO_(0.8)F_(0.2) studied by torque magnetometry
• Point-contact Andreev-reflection spectroscopy in ReFeAsO_{1-x}F_x (Re = La, Sm): Possible evidence for two nodeless gaps
• Measurement of a Sign-Changing Two-Gap Superconducting Phase in Electron-Doped Ba(Fe_{1-x}Co_x)_2As_2 Single Crystals using Scanning Tunneling Spectroscopy
• Thermal properties of SmFeAs(O1-xFx) as probe of the interplay between electrons and phonons
• Pairing symmetry and properties of iron-based high temperature superconductors
• Enhanced Orbital Degeneracy in Momentum Space for LaOFeAs
• Orbital fluctuation mechanism for superconductivity in iron-based compounds
• Theory of Andreev reflection in junctions with iron-based High-$T_c$ superconductors
• Investigation of Superconducting Gap Structure in TbFeAsO${}_{0.9}$F${}_{0.1}$ using Point Contact Andreev Reflection
• Spontaneous spin accumulation in singlet-triplet Josephson junctions
• Upper critical field, superconducting energy gaps, and Seebeck coefficient in La0.8Th0.2OFeAs
• Valence band and core level photoemission spectros-copy of LaFeAsO${}_{1-x}$F${}_x$
• Vortex state in iron-based superconductors with collinear antiferromagnetic cores
• Penetration depth, lower critical fields, and quasiparticle conductivity in Fe-arsenide superconductors
• Supercell studies of the Fermi surface changes in the electron-doped superconductor LaFeAsO${}_{1-x}$F${}_x$
• Magnetic torque study of the temperature dependent anisotropy parameter in overdoped superconducting single-crystal YBa_2Cu_3O_7
• Anisotropic superconducting properties of aligned Sm${}_{0.95}$La${}_{0.05}$FeAsO${}_{0.85}$F${}_{0.15}$ microcrystalline powder
• Constraints Imposed by Symmetry on Pairing Operators for the Pnictides
• Unconventional superconductivity originating from disconnected Fermi surfaces in the iron-based compound
• Exploring unconventional superconductivity in PdTe via Point Contact Spectroscopy