Spin Precession Experiments for Light Axionic Dark Matter

TL;DR

This paper proposes experimental techniques using existing technology to detect axion-like dark matter across a broad mass range by observing spin precession effects, potentially surpassing current astrophysical limits.

Contribution

It introduces novel experimental methods for direct detection of axion-like dark matter over a wide mass spectrum, utilizing spin precession measurements with existing devices.

Findings

Potential to detect axion-like particles via spin precession signals.

Existing technology can measure these effects with high sensitivity.

Future experiments could significantly improve detection bounds.

Abstract

Axion-like particles are promising candidates to make up the dark matter of the universe, but it is challenging to design experiments that can detect them over their entire allowed mass range. Dark matter in general, and in particular axion-like particles and hidden photons, can be as light as roughly $10^{-22} \;\rm{eV}$ ($\sim 10^{-8} \;\rm{Hz}$), with astrophysical anomalies providing motivation for the lightest masses ("fuzzy dark matter"). We propose experimental techniques for direct detection of axion-like dark matter in the mass range from roughly $10^{-13} \;\rm{eV}$ ($\sim 10^2 \;\rm{Hz}$) down to the lowest possible masses. In this range, these axion-like particles act as a time-oscillating magnetic field coupling only to spin, inducing effects such as a time-oscillating torque and periodic variations in the spin-precession frequency with the frequency and direction set by fundamental physics. We show how these signals can be measured using existing experimental technology, including torsion pendulums, atomic magnetometers, and atom interferometry. These experiments demonstrate a strong discovery capability, with future iterations of these experiments capable of pushing several orders of magnitude past current astrophysical bounds.