Detecting the Coupling of Axion Dark Matter to Neutron Spins at Spallation Sources via Rabi Oscillation

TL;DR

This paper introduces a new method to detect axion dark matter by observing Rabi oscillations in neutron spins, potentially surpassing current experimental sensitivities within a specific mass range.

Contribution

The authors propose a novel neutron spin-based detection technique for axion dark matter using Rabi oscillations, enhancing sensitivity in a key mass window.

Findings

Potential to detect axions in the $10^{-12} - 10^{-10}$ eV mass range

Method can surpass current laboratory experiment sensitivities

Utilizes a double-Stern-Gerlach apparatus for spin transition detection

Abstract

We propose a novel detection method for axion dark matter using the Rabi oscillation of neutron spins in beam-based measurements. If axions couple to neutron spins, a background oscillating axion dark matter field would drive transitions between spin-up and spin-down neutron states in a magnetic field when the axion particle energy matches the energy gap between the spin states. The transition can be detected in a double-Stern-Gerlach-type apparatus, with the first splitter producing a pure spin-polarized neutron beam and the second splitter selecting spin-flipped signals. Our approach offers enhanced detection capability for axions within the $10^{-12} - 10^{-10} \,$eV mass window with the capability to surpass the sensitivity of current laboratory experiments.