Principles of Microwave Package Design for Superconducting Quantum Processors*

Superconducting qubits are amongst the most promising platforms towards building near term, practical quantum information processors. As the number of qubits per device increases, package design becomes an increasingly important aspect enabling efficient qubit control. Multiple, often interrelated factors such as spurious modes, conduction losses, and crosstalk impose challenges that require a comprehensive approach to package design. Here, we provide an overview of our recent work aimed at addressing these challenges, including chip-to-board interconnect design, interposer design, and material choices. We present results from simulations of these elements and corresponding physical measurements on a newly designed package.