Speaker
Description
We present a multi-mode resonant-mass strain antenna for the exploration of Gravitational Wave (GW) sources in the uncharted frequency band from around 100 kHz to 10 MHz. This region may host signals from non-standard sources, such as post-merger emission from sub-solar-mass binaries or dark matter candidates. Following an approach originally proposed by Tobar and Goryachev, the experimental technique adopts Bulk Acoustic Wave (BAW) resonators made of piezoelectric quartz crystals to convert the strain of an impinging GW into an electric signal. Cryogenic operation enhances sensitivity by improving mechanical quality factors and reducing thermal noise, while enabling the use of Superconducting QUantum Interference Devices (SQUIDs) as low-noise amplifiers. FPGA-based acquisition allows for digital lock-in amplification and the concurrent monitoring of multiple overtones and vibration modes from the same crystal. In this presentation, after an introduction of the science case and the operating principle, we report on the project status, including the measured sensitivity of $10^{-21}$ strain / $\sqrt{\text{Hz}}$, achieved with commodity GPS resonators at 5 MHz and prospects for widening the frequency coverage with an array of multiple resonators.
| Parallel session | New Physics Searches: Dark Matter and High-Frequency Gravitational Waves |
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