We have constructed the ground-state configurations for a square-lattice Josephson network in a magnetic field H=p${\mathrm{\Phi }}_0$/${\mathit{qa}}^2$, for all p and q in the range 1≤p≤q/2 and 2≤q≤20, leading to a better understanding of the zero-temperature phase diagram. We then compute the field dependence of the ground-state energy, helicity modulus, and critical current.

• Received 12 April 1993

DOI:https://doi.org/10.1103/PhysRevB.48.3309