High-temperature superconducting bi-crystal Josephson junctions with asymmetric current biasing: the DC-SQUID configuration

摘要

DC SQUIDs were fabricated of YBCO bi-crystal Josephson junctions, with the bridges crossing the bi-crystal boundary at an inclination angle 0-70°. Critical current dependencies on external magnetic field were measured and studied. The presence of a bridge with a high (>45°) inclination angle in the SQUID results in strong asymmetry of the modulation peaks of the I_c(H) dependence, that probably results from deviation of the current-phase relation of such a junction from the ordinary sine form.