Ultracoherent GHz Diamond Spin-Mechanical Lamb Wave Resonators

TL;DR

This paper presents an all-optical diamond Lamb wave resonator with a GHz fundamental mode and high Q-factor, enabling advanced quantum spin-mechanics experiments at cryogenic temperatures.

Contribution

It introduces a novel all-optical excitation and detection method for high-Q GHz mechanical modes in diamond Lamb wave resonators, advancing quantum spin-mechanics research.

Findings

Achieved a Q-factor >10^7 at 7 K

Demonstrated GHz fundamental compression mode

Developed optical methods for excitation and detection

Abstract

We report the development of an all-optical approach that excites the fundamental compression mode in a diamond Lamb wave resonator with an optical gradient force and detects the induced vibrations via strain coupling to a silicon vacancy center, specifically, via phonon sidebands in the optical excitation spectrum of the silicon vacancy. Sideband optical interferometry has also been used for the detection of the in-plane mechanical vibrations, for which conventional optical interferometry is not effective. These experiments demonstrate a GHz fundamental compression mode with a Q-factor >10^7 at temperatures near 7 K, providing a promising platform for reaching the quantum regime of spin mechanics, especially phononic cavity QED of electron spins.