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 ({\it in-layer}) magnetic field we find that the oscillations of the critical current $I_c(\Phi)$ with the magnetic flux $\Phi$ are significantly different from an ordinary magnetic interference pattern. Depending on the ratio $L/D$ and temperature, $I_c(\Phi)$-oscillations can have a period smaller than flux quantum $\Phi_0$, nonzero minima and damping rate much smaller than $1/\Phi$. Similar anomalous magnetic interference pattern was recently observed experimentally.