Field and Temperature Dependence of the Superfluid Density in LaO_{1-x}F_xFeAs Superconductors: A Muon Spin Relaxation Study

Abstract

We present zero field and transverse field \muSR experiments on the recently discovered electron doped Fe-based superconductor LaO_{1-x}F_xFeAs. The zero field experiments on underdoped (x=0.075) and optimally doped (x=0.1) samples rule out any static magnetic order above 1.6 K in these superconducting samples. From transverse field experiments in the vortex phase we deduce the temperature and field dependence of the superfluid density. Whereas the temperature dependence is consistent with a weak coupling BCS s-wave or a dirty d-wave gap function scenario, the field dependence strongly evidences unconventional superconductivity. We obtain the in-plane penetration depth of λ_{ab} (0) = 254(2)nm for LaO_{0.9}F_{0.1}FeAs and λ_{ab} (0) = 364(8)nm for LaO_{0.925}F_{0.075}FeAs. Further evidence for unconventional superconductivity is provided by the ratio of T_c versus the superfluid density, which is close to the Uemura line of hole doped high-T_c cuprates.

5 pages, 5 figures

References in corpus (15)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Competing Orders and Spin-Density-Wave Instability in La(O${}_{1-x}$F${}_x$)FeAs
• Is LaO${}_{1-x}$F${}_x$FeAs an electron-phonon superconductor ?
• Very High Field Two-Band Superconductivity in LaFeAsO_0.89F_0.11
• Proximity of antiferromagnetism and superconductivity in LaO${}_{1-x}$F${}_x$FeAs: effective Hamiltonian from ab initio studies
• Doping-dependent Phase Diagram of LaO{\it M}As ({\it M}=V--Cu) and Electron-type Superconductivity near Ferromagnetic Instability
• Electron Correlations in the Low Carrier Density LaFeAsO0.89F0.11 Superconductor (Tc = 28 K)
• Iron-based layered superconductor LaO${}_{1-x}$F${}_x$FeAs: an antiferromagnetic semimetal
• Upper critical field, Hall effect and magnetoresistance in the iron-based layered superconductor LaFeAsO_{0.9}F_{0.1-δ}
• Hall effect and magnetoresistance in the normal state of the superconductor LaO${}_{0.9}$F${}_{0.1-x}$FeAs
• 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 $La(O_{1-x}{F}_x)FeAs$
• Optical determination of the superconducting energy gap in electron-doped Pr_{1.85}Ce_{0.15}CuO_4
• Study of the in-plane magnetic penetration depth in the cuprate superconductor Ca_2-xNa_xCuO_2Cl_2: role of the apical sites

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• 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${}_2$
• Interplay of Rare Earth and Iron magnetism in RFeAsO with R = La, Ce, Pr, and Sm: A muon spin relaxation study and symmetry analysis
• Coexistence of magnetic fluctuations and superconductivity in the pnictide high temperature superconductor SmFeAsO${}_{1-x}$F${}_x$ measured by muon spin rotation
• Evidence for Two Gaps and Breakdown of the Uemura Plot in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Single Crystals
• Muon-spin rotation studies of SmFeAsO_0.85 and NdFeAsO_0.85 superconductors
• Strong-coupling Spin-singlet Superconductivity with Multiple Full Gaps in Hole-doped Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Probed by Fe-NMR
• Muon spin relaxation studies of magnetic order and superfluid density in antiferromagnetic NdOFeAs, BaFe2As2 and superconducting (Ba,K)Fe2As2
• High-Field Pauli-Limiting Behavior and Strongly Enhanced Upper Critical Magnetic Fields near the Transition Temperature of an Arsenic-Deficient LaO_0.9F_0.1FeAs_(1-δ) Superconductor
• Nodal Superconductivity with Multiple Gaps in SmFeAsO${}_{0.9}$F${}_{0.1}$
• Normal State Correlated Electronic Structure of Iron Pnictides
• MuSR studies of RE(O,F)FeAs (RE = La, Nd, Ce) and LaOFeP systems: possible incommensurate/stripe magnetism and superfluid density
• Lower Critical Fields of Superconducting PrFeAsO${}_{1-y}$ Single Crystals
• Evidence for electromagnetic granularity in the polycrystalline iron-based superconductor LaO0.89F0.11FeAs
• Coexistence of two order parameters and a pseudogaplike feature in the iron-based superconductor LaFeAsO_(1-x)F_x
• Caloric Determination of the Upper Critical Fields and Anisotropy of NdFeAsO1-xFx Single Crystals
• 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
• Evidence for two distinct anisotropies in the oxypnictide superconductors SmFeAsO_(0.8)F_(0.2) and NdFeAsO_(0.8)F_(0.2)
• Upper and lower critical fields in NdFeAs(O,F) single crystals : a study by Hall probe magnetization and specific heat
• Enhancement of Superfluid Stiffness, Suppression of Superconducting T_c and Field-induced Magnetism in the Pnictide Superconductor LiFeAs
• Pairing symmetry and properties of iron-based high temperature superconductors
• Insular superconductivity in Co-doped iron pnictide CaFe${}_{1-x}$Co${}_x$AsF
• Multiple Gaps and Superfluid Density from Interband Pairing in Iron Oxypnictides
• Full Gap Superconductivity in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Probed by Muon Spin Rotation
• Electronic properties of LaOFFeAs in the normal state probed by NMR/NQR
• Energy-scale phenomenology and pairing via resonant spin-charge motion in FeAs, CuO, heavy-fermion and other exotic superconductors
• Competition/Coexisitence of Magnetism and Superconductivity in Iron Pnictides Probed by Muon Spin Rotation
• Vortex state in iron-based superconductors with collinear antiferromagnetic cores
• Optical Study of LaO_0.9F_0.1FeAs: Evidence for a Weakly Coupled Superconducting State
• Correlated electrons in Fe-As compounds: a quantum chemical perspective
• Supercell studies of the Fermi surface changes in the electron-doped superconductor LaFeAsO${}_{1-x}$F${}_x$
• Scanning tunneling microscopy of the 32 K superconductor (Sr1-xKx)Fe2As2
• Conventional Superconductivity in Fe-Based Pnictides: the Relevance of Intra-Band Electron-Boson Scattering
• Determination of characteristic muon precession and relaxation signals in FeAs and FeAs2, possible impurity phases in pnictide superconductors
• Unconventional superconductivity originating from disconnected Fermi surfaces in the iron-based compound