d-like Symmetry of the Order Parameter and Intrinsic Josephson Effects in Bi2212 Cross-Whisker Junctions

TL;DR

This study demonstrates that Bi-2212 cross-whisker junctions exhibit d-wave symmetry in their order parameter and display intrinsic Josephson effects, with a stronger angular dependence than conventional d-wave symmetry.

Contribution

It provides experimental evidence of d-wave symmetry and intrinsic Josephson effects in Bi-2212 cross-whisker junctions, revealing a stronger angular dependence than previously known.

Findings

Angular dependence of critical current density shows d-wave symmetry

Multiple-branch I-V characteristics indicate intrinsic Josephson junction array

Strong angular dependence exceeds that of conventional d-wave symmetry

Abstract

An intrinsic tunnel junction was made using two Bi-2212 single crystal whiskers. The two whiskers with a cross-angle were overlaid at their c-planes and connected by annealing. The angular dependence of the critical current density along the c-axis is of the d-wave symmetry. However, the angular dependence is much stronger than that of the conventional d-wave. Furthermore, the current vs. voltage characteristics of the cross-whiskers junctions show a multiple-branch structure at any cross-angle, indicating the formation of the intrinsic Josephson junction array.