Minimally-diffracting quartz for ultra-low temperature surface acoustic wave resonators

TL;DR

This paper identifies a specific quartz orientation that reduces diffraction losses in surface acoustic wave resonators at ultra-low temperatures, enabling high-quality quantum device applications.

Contribution

It introduces a novel quartz orientation optimized for ultra-low temperature SAW resonators, demonstrating significantly improved quality factors.

Findings

Internal quality factors >100,000 at mK temperatures

Reduced diffraction losses in the optimized quartz orientation

Enhanced suitability for quantum technologies

Abstract

We simulate and experimentally demonstrate the existence of an orientation of quartz which minimizes diffraction losses in surface acoustic wave (SAW) resonators at ultra-low temperatures. The orientation is optimized for applications to quantum technologies which benefit from high mechanical quality factors, strong electromechanical coupling, and narrow acoustic apertures. We fabricate narrow aperture SAW resonators on this substrate and measure internal quality factors greater than 100,000 at mK temperatures.