Dielectric Haloscopes as Gravitational Wave Detectors

TL;DR

Dielectric haloscopes, originally for axion detection, are proposed as promising high-frequency gravitational wave detectors with potential broadband operation and high strain sensitivities, expanding the search capabilities in the GHz to MHz range.

Contribution

This paper introduces the novel idea of using dielectric haloscopes as gravitational wave detectors, leveraging their resonant and broadband modes for enhanced sensitivity at high frequencies.

Findings

Potential strain sensitivities down to 10^{-21} Hz^{-1/2} at GHz frequencies.

Resonant setups could reach sensitivities of 3×10^{-23} Hz^{-1/2}.

Broadband operation extends detection range to lower frequencies (~100 MHz).

Abstract

We argue that dielectric haloscopes like MADMAX, originally designed for detecting axion dark matter, are also very promising gravitational wave detectors. Operated in resonant mode at frequencies around $\mathcal{O}(10\,\text{GHz})$, these detectors benefit from enhanced gravitational wave to photon conversion at the surfaces of a stack of thin dielectric disks. Since the gravitational wave is relativistic, there is an additional enhancement of the signal compared to the axion case due to increased conversion probability of gravitational waves to photons in the vacuum between the disks. A gravitational wave search using a dielectric haloscope imposes stringent requirements on the disk thickness and placement, but relaxed requirements on the disk smoothness. An advantage is the possibility of a broadband or hybrid resonant/broadband operation mode, which extends the frequency range down to $\mathcal{O}(100\,\text{MHz})$. We show that strain sensitivities down to $10^{-21} \text{Hz}^{-1/2} \times (10\,\text{GHz}/f)$ will be possible in the coming years for the broadband setup, while a resonant setup optimized for gravitational waves could even reach $3\times 10^{-23} \text{Hz}^{-1/2} \times (10\,\text{GHz}/f)$ with current technology.