Improving the performance of superconducting microwave resonators in magnetic fields

TL;DR

This paper demonstrates that introducing micropatterned pinning sites in superconducting Nb resonators significantly reduces vortex-induced energy losses, enhancing performance in magnetic fields relevant for quantum and detector applications.

Contribution

The study provides experimental evidence that antidot patterning in Nb resonators decreases vortex losses, improving quality factors in magnetic fields, a novel approach for superconducting device optimization.

Findings

Antidot patterning reduces vortex losses in Nb resonators.

Quality factors are improved across various frequencies and powers.

Performance enhancement is observed in moderate magnetic fields.

Abstract

The operation of superconducting coplanar waveguide cavities, as used for circuit quantum electrodynamics and kinetic inductance detectors, in perpendicular magnetic fields normally leads to a reduction of the device performance due to energy dissipating Abrikosov vortices. We experimentally investigate the vortex induced energy losses in such Nb resonators with different spatial distributions of micropatterned pinning sites (antidots) by transmission spectroscopy measurements at 4.2 K. In comparison to resonators without antidots we find a significant reduction of vortex induced losses and thus increased quality factors over a broad range of frequencies and applied powers in moderate fields.