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.
Researchers at MIT have presented an approach to microwave package design focusing on material choices, signal line engineering, and spurious mode suppression.
They have provided 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 µs.
The microwave package design guidelines presented address many issues relevant for near-term quantum processors.