SQUID microscope read-out on a Josephson junction array

LTC Josephson junction arrays (JJA) have recently gained interest as a model for the study of magnetization in superconductor materials. The presence of paramagnetic Meissner effect in such devices when field-cooled makes them an excellent candidate to discriminate between the different explanations given for such phenomenon. On the other hand, the understanding of the JJA physics is not simple due to the interplay between the non-linear behaviour of Josephson devices and the mutual induction effects in large JJA. The use of a SQUID microscope (SSM) to catch the magnetic image of the array is a distinctive feature of the experiment. So a study of SQUID read-out based on the actual JJA magnetic behaviour is needed in order to have a correct picture of what is going on. In this paper, using a simple way to reconstruct the complex array far-field viewed by the SQUID, we study how the flux read-out is dependent on array resolution, distance, tilting and noise for the typical situations in which arrays are found. This paper was presented at the 8th International Superconductive Electronics Conference, Osaka, Japan, 19–22 June 2001