Recent experimental work on point-contact dc squid

A toroidal point-contact dc SQUID has been successfully operated. A large input coil with Li = 64?H was coupled with ?2 = 0.34 without creasing the rf inductance of the dc SQUID by means of "capacitive shunt." The observed values of IcR = 200?V, and are close to those required for quantum-limited limited sensitivity. Noise characteristics of this SQUID are being investigated using an rf SQUID readout.