Coplanar Waveguide Resonators for Circuit Quantum Electrodynamics

TL;DR

This paper reports on the design, fabrication, and analysis of superconducting coplanar waveguide resonators with high quality factors suitable for quantum information and photon detection applications.

Contribution

It introduces a comprehensive modeling approach and demonstrates high-quality resonators with tunable parameters for quantum circuit integration.

Findings

Resonators achieved frequencies from 2 to 9 GHz.

Quality factors ranged from hundreds to hundreds of thousands.

Models accurately predict resonance characteristics.

Abstract

We have designed and fabricated superconducting coplanar waveguide resonators with fundamental frequencies from 2 to $9 \rm{GHz}$ and loaded quality factors ranging from a few hundreds to a several hundred thousands reached at temperatures of $20 \rm{mK}$. The loaded quality factors are controlled by appropriately designed input and output coupling capacitors. The measured transmission spectra are analyzed using both a lumped element model and a distributed element transmission matrix method. The experimentally determined resonance frequencies, quality factors and insertion losses are fully and consistently characterized by the two models for all measured devices. Such resonators find prominent applications in quantum optics and quantum information processing with superconducting electronic circuits and in single photon detectors and parametric amplifiers.