High-Inductance Bi-SQUID

We performed an in-depth numerical analysis of high-inductance bi-SQUIDs with normalized inductance of its one junction loop l ≫ 1. This is desired for better coupling with the external signals and for the high-temperature superconductor implementations. Typically the high linearity (up to 90 dB) can be achieved in bi-SQUIDs at l ≫ 1 at which its flux-to-voltage characteristic has a distinct triangular shape. We showed that the high linearity can be also achieved at l > 1, when the bi-SQUID has a hysteretic response. The critical current of the third Josephson junction is to be of the same order as the one of the other two Josephson junctions, and the inductance lDC of the second (two junction) loop is allowed to be as high as about one-fourth in the presence of the high linearity.