Effect of self-induced flux in parallel arrays of Josephson junctions

We have studied the self-field effect on a parallel array of 21 Josephson junctions based on an ion-damaged barrier technology [1]. The device is made of 2 chips: a superconducting chip integrating the Josephson junction array, and another chip with single layer of normal metal (gold) patterned with a grid of parallel stripes. These chips are assembled in a piggy-back configuration, and wire bonded in such a way that the bias current flowing through the array can be drained in different positions with respect to the Josephson array. As expected, we observed that the antipeak of the voltage response to an applied magnetic field was shifted by the proximity of the drained current. In addition, we observed a change in the shape of the response which we attribute to a change of the supercurrent distribution in the array. This geometry will allow proper biasing of large parallel and 2D arrays of Josephson junctions.