Piezoelectric Bulk Acoustic Resonators For Dark Photon Detection

TL;DR

This paper proposes using piezoelectric bulk acoustic resonators to detect dark photon dark matter by resonantly exciting phonons with the dark electric field, offering a highly sensitive method surpassing current experiments.

Contribution

It introduces a novel application of piezoelectric bulk acoustic resonators for dark photon detection, leveraging their high-quality phonon modes for enhanced sensitivity.

Findings

A 10 g piezoelectric BAR can outperform current experiments in sensitivity.

Resonant excitation of BAR phonons by dark electric fields is feasible.

Detection sensitivity improves significantly with a month-long exposure.

Abstract

The kinetically mixed dark photon is a simple, testable dark matter candidate with strong theoretical motivation. Detecting the feeble electric field dark photon dark matter produces requires extremely sensitive detectors. Bulk acoustic resonators (BARs), with their exceptionally high-quality phonon modes, are capable of achieving incredible sensitivity to gravitational waves in the MHz to GHz frequency range. The BAR phonons are typically read out by detecting the electric field generated by the BAR materials' piezoelectricity. Here we show that this piezoelectricity also rewards such detectors sensitivity to dark photon dark matter, as the dark electric field can resonantly excite BAR phonons. A single 10 g piezoelectric BAR in a large, cold, environment can be orders of magnitude more sensitive to the kinetic mixing parameter than any current experiment, with only a month-long exposure and thermally-limited backgrounds.