Magnetic interference pattern in planar SNS Josephson junctions

Abstract

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 ${I}_{c}(\ensuremath{\Phi})$ with the magnetic flux $\ensuremath{\Phi}$ are significantly different from an ordinary magnetic interference pattern. Depending on the ratio $L∕D$ and temperature, ${I}_{c}(\ensuremath{\Phi})$ oscillations can have a period smaller than flux quantum ${\ensuremath{\Phi}}_{0}$, nonzero minima, and damping rate much smaller than $1∕\ensuremath{\Phi}$. A similar anomalous magnetic interference pattern was recently observed experimentally.