Microwave Package Design for Superconducting Quantum Processors

TL;DR

This paper presents a microwave package design approach for superconducting quantum processors that enhances qubit performance by optimizing materials and geometry, validated through simulations and measurements.

Contribution

It introduces new design guidelines for microwave packaging that suppress spurious modes and support long qubit lifetimes, aiding scalable quantum computing.

Findings

No spurious modes up to 11GHz in the package

Supports qubits with lifetimes over 350 microseconds

Validated design through simulations and measurements

Abstract

Solid-state qubits with transition frequencies in the microwave regime, such as superconducting qubits, are at the forefront of quantum information processing. However, high-fidelity, simultaneous control of superconducting qubits at even a moderate scale remains a challenge, partly due to the complexities of packaging these devices. Here, we present an approach to microwave package design focusing on material choices, signal line engineering, and spurious mode suppression. We describe design guidelines validated using simulations and measurements used to develop a 24-port microwave package. Analyzing the qubit environment reveals no spurious modes up to 11GHz. The material and geometric design choices enable the package to support qubits with lifetimes exceeding 350 {\mu}s. The microwave package design guidelines presented here address many issues relevant for near-term quantum processors.