Quantum Enhanced Dark-Matter Search with Entangled Fock States in High-Quality Cavities

TL;DR

This paper proposes a quantum-enhanced method using entangled superconducting cavities to improve the detection of wave-like dark matter, achieving higher scan rates than classical methods and demonstrating practical feasibility with current technology.

Contribution

It introduces a novel quantum protocol utilizing entangled Fock states in high-Q cavities for dark matter detection, enhancing sensitivity and scan speed over classical approaches.

Findings

Scan rate scales as N^2(m+1), surpassing classical methods.

Robustness against noise sources is theoretically and numerically validated.

Experimental feasibility is confirmed with existing superconducting cavity technology.

Abstract

We present a quantum-enhanced protocol for detecting wave-like dark matter using an array of $N$ entangled superconducting cavities initialized in an $m$-photon Fock state. By distributing and recollecting the quantum state with an entanglement-distribution operation, the scan rate scales as $N^2(m+1)$ while thermal excitation is the dominant background, significantly outperforming classical single-cavity methods under matched conditions. We evaluate the robustness of our scheme against additional noise sources, including decoherence and beamsplitter infidelity, through theoretical analysis and numerical simulations. In practice, the key requirements, namely high-Q superconducting radio-frequency cavities that support long integration times, high-fidelity microwave beamsplitters, and universal cavity control, are already available on current experimental platforms, making the protocol experimentally feasible.