Operating characteristics of thin-film rf-biased SQUID’s

Abstract
Operating characteristics of rf‐biased thin‐film SQUID’s of diameter as large as 1 cm are reported. Observation on these SQUID’s have experimentally verified several of their conventionally assumed properties such as the dependence of the quantum interference signal on critical current of the weak link, total inductance of the SQUID, inductive coupling between drive coil and the SQUID, and random magnetic flux noise. A simple technique of lowering the inductance, and hence increasing the signal, of large‐diameter SQUID’s is reported.