INFLUENCE OF INDUCED MAGNETIC-FIELDS ON THE STATIC PROPERTIES OF JOSEPHSON-JUNCTION ARRAYS

The static properties of vortices in an array of Josephson junctions are shown to be significantly influenced by magnetic fields induced by the vortex currents. The energy barrier for vortex motion is enhanced, nearly doubling for penetration depths on the order of a cell size. Moreover, we find that correct calculation of the vortex current distribution, the magnetic moment, and the lower critical field require modeling mutual-inductance interactions between all cell pairs in the array. To make numerical simulation of the system feasible, an algorithm is derived that is sufficiently efficient to allow study of large (500 x 500 cells) arrays.