Superconducting multiple loop quantum interferometers

We present experimental results on the magnetic field B dependent voltage r esponse V(B) of a number of N resistively shunted Josephson junctions conne cted in parallel by a multiple loop network. For an appropriate distributio n or the array Loop sizes such networks constitute superconducting quantum interference filters (SQIFs) with voltage response functions V(S) that are not Go-periodic. The voltage response of SQIFs is a unique function around a global minimum at B = 0 that has a high sensitivity and a low noise level . In contrast to conventional superconducting quantum interference devices, SQIFs can be directly employed as highly sensitive magnetometers allowing the absolute measurement of magnetic fields. The experimental results are i n very good agreement with the theoretical predictions on which basis the S QIF has been fabricated. All findings suggest that superconducting quantum interference filters may allow the design of novel superconducting devices.