Trap for the Invisible: How to Catch Dark Matter ⚡ экспресс
The search for ultralight bosonic dark matter with masses in the meV range (Compton frequencies in the terahertz regime) is hindered by the difficulty of efficiently converting and detecting single photons at THz frequencies. A hybrid architecture is proposed, combining a dielectric haloscope, a Rydberg atomic converter, and superconducting nanowire detection on a single cryogenic platform at temperatures ≲1 K. The haloscope converts dark matter into THz photons via phase matching and resonant enhancement, achieving a form factor C~0.4 and a loaded quality factor Q_L~10^4. A cold ensemble of 87Rb coherently upconverts the THz signal to the optical range through six-wave mixing of Rydberg states, with inherent directionality and narrow bandwidth (~1 MHz) suppressing isotropic thermal background. With a 10-day integration at 0.3 K, the projected sensitivity to the axion-photon coupling constant is g~10^{-13} GeV^{-1} for an axion mass of ~0.4 meV, reaching the QCD axion band and opening a THz window for searches of both axion and dark photon dark matter.
Dark matter is an invisible mass holding galaxies together. Its nature remains unknown, but one likely candidate is the axion — an ultra-light particle that barely interacts with matter. To catch it, physicists built a hybrid trap.
The trap consists of a layered transparent resonator. As an axion flies through it, with a tiny probability it transforms into a photon of invisible terahertz radiation. The layers amplify this moment many times. Then rubidium atoms, bloated to gigantic sizes (Rydberg atoms), catch that photon and emit a visible flash. A superconducting nanowire at the output registers even a single quantum. After 10 days of measurements, the detector will probe axions at the level predicted by the quantum theory of strong interactions — QCD axions. This would be the first direct contact with dark matter.
🎯 The name 'axion' was inspired by a laundry detergent brand: physicists hoped the particle would 'wash away' inconsistencies in the theory.