Gravitational Wave Detection with High Frequency Phonon Trapping Acoustic Cavities

TL;DR

This paper proposes a novel high-frequency gravitational wave detector using cryogenic quartz acoustic cavities and SQUID amplifiers, capable of wide bandwidth detection and scalable into arrays for improved sensitivity.

Contribution

Introduction of a new high-frequency GW detector design utilizing ultra-high Q quartz acoustic cavities coupled with quantum-limited amplifiers, enabling wide bandwidth and scalable detection.

Findings

Spectral strain sensitivity of 10^{-22} per √Hz per mode.

Potential to cover 10^6-10^9 Hz frequency range with over 100 modes.

Scalable system suitable for array implementation and coincidence detection.

Abstract

There are a number of theoretical predictions for astrophysical and cosmological objects, which emit high frequency ($10^6-10^9$~Hz) Gravitation Waves (GW) or contribute somehow to the stochastic high frequency GW background. Here we propose a new sensitive detector in this frequency band, which is based on existing cryogenic ultra-high quality factor quartz Bulk Acoustic Wave cavity technology, coupled to near-quantum-limited SQUID amplifiers at $20$~mK. We show that spectral strain sensitivities reaching $10^{-22}$ per $\sqrt{\text{Hz}}$ per mode is possible, which in principle can cover the frequency range with multiple ($>100$) modes with quality factors varying between $10^6-10^{10}$ allowing wide bandwidth detection. Due to its compactness and well established manufacturing process, the system is easily scalable into arrays and distributed networks that can also impact the overall sensitivity and introduce coincidence analysis to ensure no false detections.