In-situ Broadband Cryogenic Calibration for Two-port Superconducting Microwave Resonators

TL;DR

This paper presents a novel in-situ broadband cryogenic calibration method for superconducting microwave resonators, significantly reducing calibration time and improving measurement accuracy by leveraging multiple measurements as a pseudo-Open standard.

Contribution

The authors develop an improved calibration technique that integrates multiple measurements as a pseudo-Open standard, enabling accurate in-situ calibration without multiple thermal cycles.

Findings

Significantly reduces calibration time from 12 days to 20 minutes.

Improves the accuracy of the measured scattering matrix of superconducting resonators.

Demonstrates successful implementation using cryogenic switches in a cryogenic environment.

Abstract

We introduce an improved microwave calibration method for use in a cryogenic environment, based on a traditional three-standard calibration, the Thru-Reflect-Line (TRL) calibration. The modified calibration method takes advantage of additional information from multiple measurements of an ensemble of realizations of a superconducting resonator, as a new pseudo-Open standard, to correct errors in the TRL calibration. We also demonstrate an experimental realization of this in-situ broadband cryogenic calibration system utilizing cryogenic switches. All calibration measurements are done in the same thermal cycle as the measurement of the resonator (requiring only an additional 20 minutes), thus avoiding 4 additional thermal cycles for traditional TRL calibration (which would require an additional 12 days). The experimental measurements on a wave-chaotic microwave billiard verify that the new method significantly improves the measured scattering matrix of a high-quality-factor superconducting resonator.