Spontaneous flux and magnetic-interference patterns in 0 Josephson junctions

The spontaneous flux generation and magnetic field modulation of the critical current in a 0-(Formula presented) Josephson junction are calculated for different ratios of the junction length (Formula presented) to the Josephsen penetration depth (Formula presented) and different ratios of the (Formula presented)-junction length to the (Formula presented)-junction length. These calculations apply to a Pb-YBa(Formula presented)Cu(Formula presented)O(Formula presented) (YBCO) (Formula presented)-axis-oriented junction with one YBCO twin boundary, as well as other experimental systems. Measurements of such a junction can provide information on the nature of the (Formula presented)-axis Josephson coupling and the symmetry of the order parameter in YBCO. We find spontaneous flux even for very short symmetric 0-(Formula presented) junctions, but asymmetric junctions have qualitatively different behavior. © 1997 The American Physical Society.