TY - JOUR
T1 - Ambegaokar-Baratoff relations for Josephson critical current in heterojunctions with multigap superconductors
AU - Ota, Yukihiro
AU - Nakai, Noriyuki
AU - Nakamura, Hiroki
AU - Machida, Masahiko
AU - Inotani, Daisuke
AU - Ohashi, Yoji
AU - Koyama, Tomio
AU - Matsumoto, Hideki
PY - 2010/6/10
Y1 - 2010/6/10
N2 - An extension of the Ambegaokar-Baratoff relation to a superconductor- insulator-superconductor (SIS) Josephson junction with multiple tunneling channels is derived. Applying the resultant relation to a SIS Josephson junction formed by an iron-based (five-band) and a single-band Bardeen-Cooper-Schrieffer (BCS) type superconductors, a theoretical bound of the Josephson critical current (I c) multiplied by the resistance of the junction (R n) is given. We reveal that such a bound is useful for identifying the pairing symmetry of iron-pnictide superconductors. One finds that if a measured value of I c R n is smaller than the bound then the symmetry is ±s wave, and otherwise s wave without any sign changes. In addition, we stress that temperature dependence of I c R n is sensitive to the difference of the gap functions from the BCS type gap formula in the above heterojunction.
AB - An extension of the Ambegaokar-Baratoff relation to a superconductor- insulator-superconductor (SIS) Josephson junction with multiple tunneling channels is derived. Applying the resultant relation to a SIS Josephson junction formed by an iron-based (five-band) and a single-band Bardeen-Cooper-Schrieffer (BCS) type superconductors, a theoretical bound of the Josephson critical current (I c) multiplied by the resistance of the junction (R n) is given. We reveal that such a bound is useful for identifying the pairing symmetry of iron-pnictide superconductors. One finds that if a measured value of I c R n is smaller than the bound then the symmetry is ±s wave, and otherwise s wave without any sign changes. In addition, we stress that temperature dependence of I c R n is sensitive to the difference of the gap functions from the BCS type gap formula in the above heterojunction.
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U2 - 10.1103/PhysRevB.81.214511
DO - 10.1103/PhysRevB.81.214511
M3 - Article
AN - SCOPUS:77955898915
SN - 1098-0121
VL - 81
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 21
M1 - 214511
ER -