Interface roughness and proximity effect on ac-axis Josephson junction betweens-wave andd-wave superconductors

Weiyi Zhang, Z. D. Wang
2002 Physical Review B (Condensed Matter)  
The scanning superconducting quantum interference device microscope on tri-crystal high-temperature superconductor ͑HTSC͒ samples unambiguously identifies the d-wave pairing symmetry as a predominant component. This fact was also seen clearly from the current phase relation ͑CPR͒ for an in-plane junction between HTSC's, where both periodicity and 2 periodicity are observed, depending on the relative crystal orientation. However, for c-axis junctions between HTSC's and conventional
more » ... , ac Josephson effect shows that the main Shapino steps occur at Vϭnh f /2e (n is integer͒ and thus a significant s-wave component is indicated. To understand the experimental measurements, we have studied interface roughness and proximity effect on CPR of such junctions. The order parameter profiles and current phase relation are computed selfconsistently using the quasiclassical theory and rough interface model. Our results suggest that the existence of a minor surface s-wave component stemming from a repulsive s-channel pairing potential in the d-wave superconductor is able to give a coherent picture.
doi:10.1103/physrevb.65.144527 fatcat:4vz4546jpzfhncn3voezmttfxe