High-Throughput Microwave Package for Precise Superconducting Device Measurement

TL;DR

This paper presents a novel, high-throughput microwave package for superconducting quantum devices that simplifies measurement setup and enables rapid, accurate characterization of device loss properties.

Contribution

The work introduces a wirebond-free, PCB-free superconducting microwave package with a suspended tungsten pin, enabling efficient and precise device loss measurements.

Findings

Achieved less than 3 dB ripple across 4-8 GHz band.

Measured superconducting resonator loss tangent of (1.10 ± 0.09) x 10^-6.

Demonstrated compatibility with existing superconducting device measurements.

Abstract

Cryogenic microwave measurement of superconducting quantum devices is complicated by the packaging required to connect devices to control and readout circuitry. In this work, we outline the design and experimental demonstration of a wirebond-free, PCB-free, drop-in microwave package for on-chip superconducting quantum devices. The package is composed of a superconducting aluminum cavity with a suspended tungsten transmission pin. The fundamental package cavity mode is far detuned from the 4 GHz to 8 GHz band of interest, and the pin transmission exhibits less than 3 dB of ripple across this range. We demonstrate the use of this package to extract the loss tangent of superconducting ring resonators, measuring a value of (1.10 +- 0.09) x 10^-6, which agrees with measurements of lambda/4 resonators in wirebond-based packaging. This high-throughput measurement system will allow the rapid generation of large datasets for improving superconducting qubit performance, and facilitate time-sensitive surface passivation and oxide regrowth studies.