Quantum‐Squeezing‐Enabled Acceleration of Dark Matter Axion Searches in Cavity Magnonics

Quantum squeezing serves as a key nonclassical resource in quantum precision measurement and sensing. In magnon‐based axion detector (i.e., a ferromagnetic haloscope), quantum uncertainty manifests as a fundamental noise source, limiting the scan rate necessary for a comprehensive search of axion parameter space. Here, we propose a scheme to accelerate the scan rate of the axion ferromagnetic haloscope via quantum squeezing. We consider a coupled cavity‐magnonic system, where the magnon mode and the cavity mode are each coupled to a separate waveguide injected with squeezed vacuum. We show that the squeezing effect results in a wider visibility bandwidth over which high visibility is maintained, thereby improving the scan rate of the axion haloscope compared to the quantum‐limited ferromagnetic haloscope.