Speaker
Description
We present GravNet, a distributed array of quantum-enhanced haloscopes aimed at the detection of light dark matter and high-frequency gravitational waves (HFGWs) in the GHz frequency range. The experiment is based on microwave cavities permeated by strong static magnetic fields, enabling resonant conversion of axions, dark photons and light dark matter particles. In addition, the same apparatus provides sensitivity to HFGWs via the Gertsenshtein effect, whereby gravitational waves are converted into electromagnetic excitations within the cavity volume.
GravNet is designed as a network of cavities distributed across three geographically separated European sites. A key feature of the experiment is the coherent combination of the cavity outputs, achieved through time-synchronization protocols. For the HFGWs analysis, this approach enables a scaling of the detection significance as $N$, the number of detectors, surpassing the $\sqrt{N}$ scaling characteristic of incoherent averaging.
To increase the signal-to-noise ratio in each detector, the collaboration will exploit the quantum technologies currently under development, i.e. single photon detection through superconducting qubits dispersively coupled to 3D cavities. Thus, with an optimal setup, the experiment could reach strain sensitivities of $h\sim 10^{-20}$, testing the existence of primordial black hole mergers of $\sim 10^{-13}$ solar masses.
GravNet thus defines a scalable distributed haloscope network, opening a novel parameter space for light dark matter searches and high frequency gravitational waves.
| Parallel session | New Physics Searches: Dark Matter and High-Frequency Gravitational Waves |
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