Ota Yukihiro, Machida Masahiko, Koyama Tomio, Matsumoto Hideki
CCSE, Japan Atomic Energy Agency, Tokyo 110-0015, Japan.
Phys Rev Lett. 2009 Jun 12;102(23):237003. doi: 10.1103/PhysRevLett.102.237003.
Using the functional integral method, we construct a theory of heterotic superconductor-insulator-superconductor Josephson junctions between one- and two-gap superconductors. The theory predicts the presence of in-phase and out-of-phase collective oscillation modes of superconducting phases. The former corresponds to the Josephson plasma mode whose frequency is drastically reduced for +/- s-wave symmetry, and the latter is a counterpart of Leggett's mode in Josephson junctions. We also reveal that the critical current and the Fraunhofer pattern strongly depend on the symmetry type of the two-gap superconductor.
利用泛函积分方法，我们构建了一种关于单能隙和双能隙超导体之间的杂化超导 - 绝缘体 - 超导约瑟夫森结的理论。该理论预测了超导相位的同相和异相集体振荡模式的存在。前者对应于约瑟夫森等离子体模式，其频率对于±s波对称性会急剧降低，而后者是约瑟夫森结中莱格特模式的对应模式。我们还揭示了临界电流和夫琅禾费图案强烈依赖于双能隙超导体的对称类型。
