We study the Josephson current through a ballistic normal metal layer of thickness D, on which two superconducting electrodes are deposited within a distance L of each other. In the presence of an (in-layer) magnetic field, we find that the oscillations of the critical current I_c(Φ) with the magnetic flux Φ are significantly different from an ordinary magnetic interference pattern. Depending on the ratio L/D and temperature, I_c(Φ) oscillations can have a period smaller than flux quantumΦ_0, nonzero minima, and damping rate much smaller than 1/Φ. A similar anomalous magnetic interference pattern was recently observed experimentally.
展开▼
