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.

14 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 (21)

• High-temperature superconductivity in iron-based materials
• Superconductivity at 22 K in Co-doped BaFe2As2 Crystals
• 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
• Small anisotropy, weak thermal fluctuations, and high field superconductivity in Co-doped iron pnictide Ba(Fe1-xCox)2As2
• Iron based high transition temperature superconductors
• Anisotropy of the Optimally-Doped Iron Pnictide Superconductor Ba(Fe0.926Co0.074)2As2
• Upper critical field, anisotropy, and superconducting properties of Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ single crystals
• 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
• Emergent phenomena in multicomponent superconductivity: an introduction to the focus issue
• Angular dependence of resistivity in the superconducting state of NdFeAsO${}_{0.82}$F${}_{0.18}$ single crystals
• Anisotropic type-I superconductivity and anomalous superfluid density in OsB 2
• Enhancement of critical current density in (Ba,Na)Fe2As2 round wires using high-pressure sintering
• 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
• 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

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