Abstract
We report measurements of the dynamic resistance of a dc SQUID formed by two contacts between two different edges of a single crystal of and a Nb block. The phase of the field-induced oscillations was compared with those of two adjacent SQUID’s, each formed by two Nb-Nb contacts. We find a phase difference of 160±30° between the oscillations of the composite SQUID and those of the SQUID’s formed by Nb-Nb junctions. A possible explanation for this reproducible effect is that this cuprate superconductor has an unconventional order parameter.
DOI:https://doi.org/10.1103/PhysRevB.50.6530
©1994 American Physical Society