Enhanced Rydberg-Atom Superheterodyne Detection of Hidden-Photon Dark Matter on Chips

Abstract

Although hidden-photon dark matter with masses above $10^{-4}\mathrm{eV}$ is well motivated by inflationary production, it remains largely unexplored by terrestrial experiments. Through kinetic mixing, hidden photons induce a weak oscillating electric field above $10\mathrm{GHz}$. We propose to amplify this signal using a compact high-frequency distributed cavity and detect it with chip-scale Rydberg-atom superheterodyne spectroscopy. Combining resonant enhancement, large dipole moments of Rydberg atoms, and long-term stable integration, this approach can probe hidden-photon dark matter in the mass range $5\times 10^{-5}\text{–}7\times 10^{-4}\mathrm{eV}$ with sensitivities $3$--$4$ orders of magnitude beyond existing limits.

14 pages, 3 figures, submitted to a journal on July 6, 2026