Signature of multigap nodeless superconductivity in fluorine-doped NdFeAsO

Abstract

We investigate the temperature dependence of the lower critical field $H_{c1}(T)$, the field at which vortices penetrate into the sample, of a high-quality fluorine-doped NdFeAsO single crystal under static magnetic fields $H$ parallel to the $c$-axis. The temperature dependence of the first vortex penetration field has been experimentally obtained and pronounced changes of the $H_{c1}$(T) curvature are observed, which is attributed to the multiband superconductivity. Using a two-band model with $s$-wave-like gaps, the temperature-dependence of the lower critical field $H_{c1}(T)$ can be well described. These observations clearly show that the superconducting energy gap in fluorine-doped NdFeAsO is nodeless. The values of the penetration depth at $T$ = 0\,K have been determined and confirm that the pnictide superconductors obey an Uemura-style relationship between $T_c$ and ${\lambda }_{ab}(0{)}^{-2}$

arXiv comment7 pages, 4 figures

References in corpus (46)

• Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• The Puzzle of High Temperature Superconductivity in Layered Iron Pnictides and Chalcogenides
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Superconductivity in Iron Compounds
• High-temperature superconductivity in iron-based materials
• Gap symmetry and structure of Fe-based superconductors
• Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO${}_{1-x}$F${}_x$FeAs
• Temperature and field dependence of the anisotropy of MgB2
• Momentum dependence of the superconducting gap in NdFeAsO1-xFx single crystals measured by angle resolved photoemission spectroscopy
• Iron based high transition temperature superconductors
• Spin-triplet p-wave pairing in a 3-orbital model for iron pnictide superconductors
• Field and Temperature Dependence of the Superfluid Density in LaO_{1-x}F_xFeAs Superconductors: A Muon Spin Relaxation Study
• Critical Fields and Anisotropy of NdO0.82F0.18FeAs Single Crystals
• Unconventional London penetration depth in Ba(Fe0.93Co0.07)2As2 single crystals
• Exponential Temperature Dependence of Penetration Depth in Single Crystal MgB_2
• Irreversible Magnetization of Pin-Free Type II Superconductors
• Elaboration of the alpha-Model Derived from the BCS Theory of Superconductivity
• Penetration depth study of superconducting gap structure of 2\textit{H}-NbSe${}_2$
• Fe-based superconductors: seven years later
• Magnetic Order of the Iron Spins in NdOFeAs
• Even Parity, Orbital Singlet and Spin Triplet Pairing for Superconducting $La(O_{1-x}{F}_x)FeAs$
• Coexistence of magnetic fluctuations and superconductivity in the pnictide high temperature superconductor SmFeAsO${}_{1-x}$F${}_x$ measured by muon spin rotation
• Doping evolution of superconducting gaps and electronic densities of states in Ba(Fe1-xCox)2As2 iron pnictides
• Evidence for Two Gaps and Breakdown of the Uemura Plot in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Single Crystals
• Temperature dependence of lower critical field Hc1(T) shows nodeless superconductivity in FeSe
• 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
• Specific heat and upper critical field in KFe2As2 single crystals
• Local density of states and superconducting gap in the iron chalcogenide superconductor Fe${}_{1+\delta }$Se${}_{1-x}$Te${}_x$ observed by scanning tunneling spectroscopy
• Non-exponential London penetration depth in Ba${}_{1-}$K${}_x$Fe${}_2$As${}_2$ single crystals
• High-pressure flux growth, structural, and superconducting properties of LnFeAsO (Ln = Pr, Nd, Sm) single crystals
• Nodal Superconductivity with Multiple Gaps in SmFeAsO${}_{0.9}$F${}_{0.1}$
• Evidence for two-gap nodeless superconductivity in SmFeAsO${}_{0.8}$F${}_{0.2}$ from point-contact Andreev-reflection spectroscopy
• Possible two-gap superconductivity in NdFeAs(O,F) probed by point-contact Andreev-reflection spectroscopy
• Interplay between Fe and Nd magnetism in NdFeAsO single crystals
• Nodal gap structure in Fe-based superconductors due to the competition between orbital and spin fluctuations
• Multi-gap superconductivity in single crystals of Ba${}_{0.65}$Na${}_{0.35}$Fe${}_2$As${}_2$: A calorimetric investigation
• Small anisotropy of the lower critical field and $s_{\pm }$-wave two-gap feature in single crystal LiFeAs
• Lower critical field and SNS-Andreev spectroscopy of 122-arsenides: Evidence of nodeless superconducting gap
• Andreev spectroscopy of iron-based superconductors: temperature dependence of the order parameters and scaling of the ${\Delta }_{L,S}$ with $T_C$
• Nodeless superconductivity in the presence of spin-density wave in pnictide superconductors: The case of BaFe${}_{2-x}$Ni${}_x$As${}_2$
• Evolution of Superconducting Gaps in Th-Substituted Sm${}_{1-x}$Th${}_x$OFeAs Studied by Multiple Andreev Reflection Spectroscopy
• Penetration depth, lower critical fields, and quasiparticle conductivity in Fe-arsenide superconductors
• Spin and mass superfluidity in ferromagnetic spin-1 Bose-Einstein condensate
• Unconventional superconductivity of NdFeAsO0.82F0.18 indicated by the low temperature dependence of the lower critical field Hc1

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• Two Dimensional Multigap Superconductivity in Bulk 2H-TaSSe
• Anisotropic Enhancement of Lower Critical Field in Ultraclean Crystals of Spin-Triplet Superconductor UTe2
• Self-consistent two-gap approach in studying multi-band superconductivity in NdFeAsO${}_{0.65}$F${}_{0.35}$
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