Theory of vortex structure in Josephson junctions with multiple tunneling channels: Vortex enlargement as a probe of $\pm s$-wave superconductivity

Abstract

We theoretically study Josephson vortex structures in Josephson junctions which have multiple tunneling channels caused by multiple superconducting gaps. Deriving "coupled sine-Gordon equations" from the free-energy taking account of the multiple tunneling channels, we examine two typical situations, a heterotic junction composed of multigap-superconductor, insulator, and single-gap superconductor, and a grain-boundary junction formed by two identical multigap superconductors. Then, we reveal in both situations that the magnetic field distribution of the Josephson vortex for $\pm s$-wave superconductivity is more enlarged than that for s-wave without sign change between the order parameters. Its mechanism is ascribed to a cancellation of the multiple Josephson currents. We display such an anomalous Josephson vortex and suggest how to evaluate the enlargement.

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Cited by in corpus (8)

• Intrinsic Josephson junctions in the iron-based multi-band superconductor (V2Sr4O6)Fe2As2
• Efficient Numerical Self-consistent Mean-field Approach for Fermionic Many-body Systems by Polynomial Expansion on Spectral Density
• Josephson effect between a two-band superconductor with the s++ or s+- pairing symmetry and a conventional s-wave superconductor
• Ground state, collective mode, phase soliton and vortex in multiband superconductors
• Ambegaokar-Baratoff relations of Josephson critical current in heterojunctions with multi-gap superconductors
• Proximity and Josephson effects in microstructures based on multiband superconductors
• Magnetic Ordering in Blocking Layer and Highly Anisotropic Electronic Structure of High-Tc Iron-based Superconductor Sr2VFeAsO3: LDA+U Studies
• Shapiro Steps as a Direct Probe of $\pm s$-wave Symmetry in Multi-gap Superconducting Josephson Junctions