Local tunneling characteristics near a grain boundary of a d-wave superconductor as probed by a normal-metal or a low-T-c-superconductor STM tip

Article

关键词: HIGH-TEMPERATURE SUPERCONDUCTORS;    BIAS CONDUCTANCE PEAK;    PAIRING SYMMETRY;    SURFACE-STATES;    ANDREEV REFLECTION;    ORDER-PARAMETER;    CURRENT-VOLTAGE;    THIN-FILMS;    JUNCTIONS;    YBA2CU3O7-DELTA;   

DOI  :  10.1103/PhysRevB.62.1308

来源: SCIE

【 摘 要 】

We study the local single-particle tunneling characteristics [as observed with scanning tunnel microscopy (STM)] for N-D and S-D tunneling, where D is a d-wave superconductor with a {100}\{110} grain boundary. The tunneling Hamiltonian method is used. The self-consistent order parameter is first determined using the quasiclassical Green's-function method, and then the tunneling characteristics at various distances from the interface, reflectivity of the interface, and temperature, are studied. For N-D tunneling, a zero-bias conductance peak (ZBCP) occurs near the interface, with diminishing magnitude away from it. For S-D tunneling, the ZBCP splits to exhibit the gap of the s-wave low-T-c superconducting tunneling tip, and there is a range of negative conductance just outside the peaks, when the tunneling point is near the grain boundary. The results are compared with those obtained by using a constant order parameter in each grain.

【 授权许可】

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