Degenerate ground state and anomalous flux hysteresis in an YBa2Cu3O7 grain boundary r.f. SQUID

C. H. Gardiner, R. A. M. Lee, J. C. Gallop +3

We report measurements of the flux hysteresis curves and trapped flux distribution in an YBa2Cu3O7 r.f. SQUID containing two closely spaced grain boundary Josephson junctions in pa…