Angle-Resolved Cryogenic Brillouin-Mandelstam Spectroscopy of Surface and Bulk Acoustic Phonons in Diamond

TL;DR

This study employs angle-resolved cryogenic Brillouin-Mandelstam spectroscopy to measure surface and bulk acoustic phonons in diamond, providing insights relevant for quantum sensors and thermal transport modeling.

Contribution

First detailed cryogenic angle-resolved measurements of surface and bulk acoustic phonons in diamond along specific crystallographic directions.

Findings

Surface acoustic phonons show less than 1.6% temperature dependence.

Measured phonon frequencies agree with theoretical predictions.

Data are relevant for quantum sensors and thermal interface models.

Abstract

We used angle-resolved Brillouin-Mandelstam light-scattering spectroscopy to monitor surface and bulk acoustic phonons in diamond along the <100> and <110> crystallographic directions across a temperature range from 10 K to 300 K. The frequencies and phase velocities were measured for three types of surface acoustic phonons: Rayleigh waves, shear horizontal waves, and high-frequency pseudo-longitudinal waves. All surface acoustic phonons exhibit weak temperature dependence, with the largest observed change of 1.6% across the examined temperature range. The frequencies of all three types of surface acoustic phonons agree with the theoretical values within the experimental uncertainty. Cryogenic surface-acoustic-phonon data are important for diamond-based quantum sensors, surface acoustic wave devices, and other electronic technologies. Knowledge of surface acoustic phonons can also be used for developing accurate models for thermal transport between interfaces.