TY - JOUR
T1 - Theory of vortex structure in Josephson junctions with multiple tunneling channels
T2 - Vortex enlargement as a probe of ±s -wave superconductivity
AU - Ota, Yukihiro
AU - Machida, Masahiko
AU - Koyama, Tomio
AU - Matsumoto, Hideki
PY - 2010/1/5
Y1 - 2010/1/5
N2 - 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 ±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.
AB - 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 ±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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U2 - 10.1103/PhysRevB.81.014502
DO - 10.1103/PhysRevB.81.014502
M3 - Article
AN - SCOPUS:77954780500
VL - 81
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 0163-1829
IS - 1
M1 - 014502
ER -