Multiband effects on the upper critical field angular dependence of 122-family iron pnictide superconductors

Abstract

Detailed measurements of the in-plane resistivity were performed in a high-quality Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ ($x=0.065$) single crystal, in magnetic fields up to 9 T and with different orientations $\theta$ relative to the crystal $c$ axis. A significant $\rho (T{)}_{H,\theta }$ rounding is observed just above the superconducting critical temperature $T_c$ due to Cooper pairs created by superconducting fluctuations. These data are analyzed in terms of a generalization of the Aslamazov-Larkin approach, that extends its applicability to high reduced-temperatures and magnetic fields. This method allows us to carry out a criterion-independent determination of the angular dependence of the upper critical field, $H_{c2}(\theta )$. In spite of the relatively small anisotropy of this compound, it is found that $H_{c2}(\theta )$ presents a significant deviation from the single-band 3D anisotropic Ginzburg-Landau (3D-aGL) approach, particularly for large $\theta$ (typically above $\sim 60^o$). These results are interpreted in terms of the multiband nature of these materials, in contrast with other proposals for similar $H_{c2}(\theta )$ anomalies. Our results are also consistent with an effective anisotropy factor almost temperature independent near $T_c$, a result that differs from the ones obtained by using a single-band model.

arXiv comment14 pages including 7 figures. This is a preprint of an article published in Scientific Reports. The final authenticated version is available online at: https://rdcu.be/clIHJ

References in corpus (50)

• Superconductivity in Iron Compounds
• High-temperature superconductivity in iron-based materials
• Gap symmetry and structure of Fe-based superconductors
• Superconductivity at 22 K in Co-doped BaFe2As2 Crystals
• Enhancement of the upper critical field by nonmagnetic impurities in dirty two-gap superconductors
• Very High Field Two-Band Superconductivity in LaFeAsO_0.89F_0.11
• Effects of Co substitution on thermodynamic and transport properties and anisotropic $H_{c2}$ in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ single crystals
• Nearly Isotropic superconductivity in (Ba,K)Fe2As2
• Recent advances in iron-based superconductors toward applications
• Fermi surface nesting induced strong pairing in iron-based superconductors
• Small anisotropy, weak thermal fluctuations, and high field superconductivity in Co-doped iron pnictide Ba(Fe1-xCox)2As2
• Iron based high transition temperature superconductors
• London Penetration Depth in Iron - based Superconductors
• Anisotropy of the Optimally-Doped Iron Pnictide Superconductor Ba(Fe0.926Co0.074)2As2
• Superconductivity in Ca1-xLaxFeAs2: A Novel 112-Type Iron Pnictide with Arsenic Zigzag Bonds
• Upper critical field, anisotropy, and superconducting properties of Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ single crystals
• Electron doped Ca10(Pt3As8)(Fe2As2)5 and Ca10(Pt4As8)(Fe2As2)5 - High Tc superconductors with skutterudite intermediary layers
• Anisotropic superconducting properties of single-crystalline FeSe0.5Te0.5
• Superconductivity at 38 K in Iron-Based Compound with Platinum-Arsenide Layers Ca10(Pt4As8)(Fe2-xPtxAs2)5
• Calorimetric Evidence of Multiband Superconductivity in Ba(Fe0.925Co0.075)2As2
• Local measurement of the penetration depth in the pnictide superconductor Ba(Fe${}_{0.95}$Co${}_{0.05}$)${}_2$As${}_2$
• Superconductivity up to 35 K in the iron-platinum arsenides (CaFe1-xPtxAs)10Pt4-yAs8 with layered structures
• Resistivity and upper critical field in KFe${}_2$As${}_2$ single crystals
• Doping evolution of the absolute value of the London penetration depth and superfluid density in single crystals of Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Local measurement of the superfluid density in the pnictide superconductor Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ across the superconducting dome
• Multigap superconductivity and strong electron-boson coupling in Fe-based superconductors: A point-contact Andreev-reflection study of Ba(Fe1-xCox)2As2 single crystals
• Muon Spin Rotation Measurement of the Magnetic Field Penetration Depth in Ba(Fe0.93 Co0.07)2 As2 : Evidence for Multiple Superconducting Gaps
• Emergent phenomena in multicomponent superconductivity: an introduction to the focus issue
• On the consequences of the uncertainty principle on the superconducting fluctuations well inside the normal state
• Highly anisotropic energy gap in superconducting Ba(Fe${}_{0.9}$Co${}_{0.1}$)${}_2$As${}_2$ from optical conductivity measurements
• Vortex dynamics and irreversibility line in optimally doped SmFeAsO${}_{0.8}$F${}_{0.2}$ from ac susceptibility and magnetization measurements
• Angular dependence of resistivity in the superconducting state of NdFeAsO${}_{0.82}$F${}_{0.18}$ single crystals
• BaT2As2 Single Crystals (T = Fe, Co, Ni) and Superconductivity upon Co-doping
• Anisotropic type-I superconductivity and anomalous superfluid density in OsB 2
• Superfluid density measurements of Ba(CoxFe1-x)2As2 films near optimal doping
• Enhancement of critical current density in (Ba,Na)Fe2As2 round wires using high-pressure sintering
• Cross-band versus intra-band pairing in superconductors: signatures and consequences of the interplay
• Two-band BCS superconductivity in Ba(Fe0.9Co0.1)2As2
• Observation of anisotropic diamagnetism above the superconducting transition in iron-pnictide Ba_(1-x)K_xFe2As2 single crystals due to thermodynamic fluctuations
• Superconducting phase fluctuations in SmFeAsO${}_{0.8}$F${}_{0.2}$ from diamagnetism at low magnetic field above $T_c$
• Angular-dependent upper critical field of overdoped Ba(Fe${}_{1-x}$Ni${}_x$)${}_2$As${}_2$
• Structural and Tc inhomogeneities inherent to doping in La_{2-x}Sr_xCuO_4 superconductors and their effects on the precursor diamagnetism
• Anisotropy of iron-platinum-arsenide Ca10(PtnAs8)(Fe2-xPtxAs2)5 single crystals
• Upper critical field anisotropy in BaFe2-xCoxAs2 single crystals synthesized without flux
• Measurements of the superconducting fluctuations in optimally-doped BaFe${}_{2-x}$Ni${}_x$As${}_2$ under high magnetic fields: Probing the 3D anisotropic Ginzburg-Landau approach
• Superconducting fluctuations in isovalently-substituted BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$: Possible observation of multiband effects
• Measurements of the fluctuation-induced in-plane magnetoconductivity at high reduced temperatures and magnetic fields in the iron arsenide BaFe(2-x)NixAs2
• Quasi-2D behavior of 112-type iron-based superconductors
• Non-conventional superconducting fluctuations in Ba(Fe1-xRhx)2As2 iron-based superconductors
• On the determination of the quasiparticle scattering rate in unconventional superconductors by microwave surface impedance

Cited by in corpus (4)

• Crossover from Conventional to Unconventional Superconductivity in 2M-WS2
• Nematic superconductivity from selective orbital pairing in Ba(Fe1-xMx)2As2 (M = Co, Ni) single crystals
• Upper critical fields in high-$T_{\mathrm{c}}$ superconductors
• Enhancement of the critical current by surface irregularities in Fe-based superconductors