势垒散射对双层d波超导结直流Josephson电流的影响
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摘要
在d波超导体/绝缘层/d波超导体(dS/I/dS)中,考虑到结界面势垒散射,运用Bogoliubov-de Gennes(BdG)方程和推广的Furusaki-Tsukada(FT)电流公式,计算了超导结中准粒子的传输系数和直流Josephson电流.研究结果表明:dS/I/dS结中的Josephson电流随着温度的变化曲线强烈依赖于d波超导体的晶轴方位,并且结界面处的势垒散射始终对Andreev反射有抑制作用.
The d.c.Josephson effect has been studied by taking into account the barrier interface scattering effect in a d-wave superconductor/insulator/d-wave superconductor junctions.We calculate the d.c.Josephson current based on the Bogoliubov de Gennes(BdG) equation and Furusaki-Tsukada(FT) formula.It is found that the d.c.Josephson current depends strongly on the crystalline axis orientation of d-wave superconductor in d-wave superconductor /insulator/d-wave superconductor junctions,the barrier strength at interface always suppress the Andreev reflection.
The d.c.Josephson effect has been studied by taking into account the barrier interface scattering effect in a d-wave superconductor/insulator/d-wave superconductor junctions.We calculate the d.c.Josephson current based on the Bogoliubov de Gennes(BdG) equation and Furusaki-Tsukada(FT) formula.It is found that the d.c.Josephson current depends strongly on the crystalline axis orientation of d-wave superconductor in d-wave superconductor /insulator/d-wave superconductor junctions,the barrier strength at interface always suppress the Andreev reflection.
引文
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[2]Asulin I,Koren G,Oded M,et al.Spatial modulation of midgap states in(001)La1.88Sr0.12CuO4 films:Indications for antiphaseordering of the d-wave order parameter[J].Phys Rev B,2010,81,024516.doi:10.1103/PhysRevB.81.024516.
[3]Van Harlingen D J.Phase-sensitive tests of the symmetry of the pairing state in the high-temperature superconductors-Evidence fordx2-y2 symmetry[J].Rev Mod Phys,1995,67,515.doi:10.1103/RevModPhys.67.515.
[4]Tanaka Y,Kashiwaya S.Theory of the Josephson effect in d-wave superconductors[J].Phys Rev B,1996,53,R11957.doi:10.1103/PhysRevB.53.R11957.
[5]Furusaki A,Tsukada M.DC Josephson effect and Andreev reflection[J].Solid State Communications,1991,78:299-302.
[6]Zhu J X,Wang Z D,Xing D Y,et al.Differential conductance of normal metal-insulator-d-wave superconductor junctions with in-terface roughness[J].Physica C:Superconductivit,1996,260,217-223.
[7]de Gennes P G.Supercouductivity of Metals and Aollys[M].New York:Benjamin,1966.
[8]Andreev A F.The thermal conductivity of the intermediate state in superconductors[J].J Exptl Theoret Phys,1964,46:1823-1828.
[9]Tanaka Y.Josephson effect between s wave and dx2-y2 wave superconductors[J].Phys Rev Lett,1994,72,3871.doi:10.1103/PhysRevLett.72.3871.
[10]Liao Y H,Dong Z C,Yin Z F,et al.Josephson current in ferromagnetic d-wave superconductor/ferromagnetic d-wave supercon-ductor junction[J].Phys Lett A,2008,372:1327-1332.
[11]Li X W.The dc Josephson current in superconductor-ferromagnet/insulator/spin-triplet p-wave superconductor junctions[J].ActaPhys Sin,2006,55,6637.doi:1000-3290/2006/55(12)/6637.