Roll-to-roll fabrication of superconducting flexible shielded high-density interconnects for scalable quantum computing

A high density wiring solution is indispensable for the scaling up of superconducting qubit-based quantum computers. With increasing numbers of qubits, implementing conventional coax cables with SMA connectors inside a cryostat is no longer feasible. Here we propose the roll-to-roll manufacturing route for a thin and flexible high-density interconnect solution based on niobium and polyimide together with a PCB-direct connector. The feasibility of this process is demonstrated by fabrication of 150 mm long flexible cables, featuring 16 shielded transmission lines which become superconducting below 6 K.