Superconducting Qubit Control with Single Flux Quantum Pulses in A Multichip Module: Part I – Fabrication and Pulse Driver

Superconducting qubits are an attractive candidate for quantum information. However, existing control techniques do not scale well to large-scale qubit arrays processing. A promising candidate for scalable control is the Single Flux Quantum (SFQ) digital logical family. In an initial implementation, the fidelity of SFQ-based qubit gates was limited by quasiparticle (QP) poisoning of the qubit induced by the dissipative SFQ pulse driver. Here we introduce a quantum-classical multichip module (MCM) where the SFQ driver and the qubit are segregated onto separate chips in order to suppress QP poisoning. We describe the design, fabrication, and thermalization of the MCM. Finally, we discuss the operation and characterization of the SFQ pulse generator and qubit.