An array of bulk-acoustic-wave sensors as a high-frequency antenna for gravitational waves

TL;DR

This paper explores using bulk acoustic wave devices as high-frequency gravitational wave detectors, proposing a multimode antenna array that could enhance sensitivity and target specific astrophysical signals.

Contribution

It introduces the BAUSCIA project plan to develop a BAW-based multimode gravitational wave antenna array with potential for improved sensitivity and frequency coverage.

Findings

Commercial BAWs have sensitivity comparable to current detectors at ~10 MHz.

Proposed custom BAWs could improve sensitivity and target specific signals.

The array can probe frequencies between 0.1 and 10 MHz.

Abstract

In their simplest form, bulk acoustic wave (BAW) devices consist of a piezoelectric crystal between two electrodes that transduce the material's vibrations into electrical signals. They are adopted in frequency control and metrology, with well-established standards at frequencies of 5~MHz and above. Their use as a resonant-mass strain antenna for high-frequency gravitational waves has been recently proposed (Goryachev and Tobar, 2014). The estimated power spectral density sensitivity at the resonant frequencies is of the order of $10^{-21}\, \textrm{strain}/\sqrt{\textrm{Hz}}$. In this paper, after introducing the science opportunity and potential of gravitational wave detection with BAWs, we describe the two-stage BAUSCIA project plan to build a multimode antenna based on commercial BAWs, followed by an optimized array of custom BAWs. We show that commercially available BAWs already provide sensitivity comparable to current experiments around 10~MHz. Finally, we outline options for optimization of custom devices to improve sensitivity in an unexplored region, probe multiple frequencies between 0.1 and 10 MHz, and target specific signals, such as post-merger emission from neutron stars or emission from various dark matter candidates.