Dark Matter Detection through Rydberg Atom Transducer

TL;DR

This paper proposes a novel hybrid detection system combining dielectric haloscope, Rydberg-atom transducer, and superconducting photon detectors to search for ultralight bosonic dark matter in the THz frequency range, achieving high sensitivity and background suppression.

Contribution

It introduces a new integrated cryogenic platform for dark matter detection that enhances signal conversion efficiency and sensitivity at THz frequencies.

Findings

Projected sensitivity to axion-photon coupling of ~10^{-13} GeV^{-1}

Achieves form factors around 0.4 and quality factors of 10^4

Reaches the QCD axion band in the THz window

Abstract

Ultralight bosonic dark matter with masses in the meV range, corresponding to terahertz (THz) Compton frequencies, remains largely unexplored due to the difficulty of achieving both efficient signal conversion and single-photon-sensitive detection at THz frequencies. We propose a hybrid detection architecture that integrates a dielectric haloscope, Rydberg-atom transducer, and superconducting nanowire single-photon detection within a unified cryogenic platform operating at $\lesssim 1\,\text{K}$. The dielectric haloscope converts dark matter into THz photons via phase-matched resonant enhancement, achieving form factors $C \sim 0.4$ and loaded quality factors $Q_L \sim 10^4$. A cold $^{87}$Rb ensemble then coherently up-converts the THz signal to the optical domain through six-wave mixing among Rydberg states. The intrinsic directionality and narrow bandwidth ($\Delta\nu_{\mathrm{atomic}} \sim 1\,\text{MHz}$) of this process provide extra suppression of isotropic thermal backgrounds. With 10 days of integration at $0.3\,\text{K}$, we project sensitivity to the axion-photon coupling $g_{a\gamma\gamma} \sim 10^{-13}\,\mathrm{GeV}^{-1}$ at $m_a \sim 0.4\,\text{meV}$, reaching the QCD axion band and opening the THz window for searches of both axion and dark photon dark matter.