Design and fabrication of integrated superconducting isolator-circulator-isolator chip

This paper presents a design and fabrication of integrated superconducting Isolator-Circulator-Isolator (ICI) chip, which is able to act as isolator and circulator simultaneously. The ICI is composed of tunable inductor bridges which based on arrays of superconducting quantum interference devices (SQUIDs). The ICI is modeled and the microwave scattering parameters are simulated by Advanced Design System© software. The ICI chip works on the frequencies between 4 and 8 GHz, and at operation temperature about 20 mK, with isolation exceeds 40 dB and insertion loss less than 4 dB. A set of 10 layout masks are designed and the chip is fabricated based on self-aligned process of Josephson junctions. The ICI can help mitigate the interconnecting bottleneck of superconducting quantum computers.