Spin precession experiments for light axionic dark matter

Abstract

Axionlike 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, axionlike particles and hidden photons, can be as light as roughly 10 −22 eV (∼10 −8 Hz), with astrophysical anomalies providing motivation for the lightest masses ("fuzzy dark matter"). We propose experimental techniques for direct detection of axionlike dark matter in the mass range from roughly 10 −13 eV (∼10 2 Hz) down to the lowest possible masses. In this range, these axionlike particles act as a time-oscillating magnetic field coupling only to spin, inducing effects such as a timeoscillating torque and periodic variations in the spin-precession frequency with the frequency and direction of these effects set by the axion field. We describe 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.

Exploring the ultra-light to sub-MeV dark matter window with atomic clocks and co-magnetometers

“…We consider two different systems that have already been used in the search of deviations from Lorentz invariance [52,53]. These set-ups were recently suggested to study axionic dark matter [54] (see also [55]). For these DM candidates, our study yields results similar to [54], though we give more explicit equations connecting the phenomenology to fundamental DM-SM couplings.…”

Axion-like relics: new constraints from old comagnetometer data

“…Our analysis lays out the machinery (distinct from that presented in Ref. [49]) needed to explore higher masses, extending the limits up to m a ∼ < 4 × 10 −13 eV. We further discuss the near-future prospects of these experiments.…”

“…[48] suggested doing an analysis such as the one presented in this paper, and Ref. [49] has implemented the analysis for the case where the ALP's inverse-mass is much larger than the total measurement time, placing limits for m a 2 × 10 −22 eV. Our analysis lays out the machinery (distinct from that presented in Ref.…”

Dark photon dark matter from a network of cosmic strings

“…The value of the string tension today is given by Eq. (5), which evaluates to µ(t 0 ) ≈ (π/2λ) m 2 ρ log[m ρ /m A ], and since this is only logarithmically sensitive to the dark photon mass, we fix m A = 10 −10 eV and show the corresponding value of µ(t 0 ) on the top of the plot.…”

“…The logarithm appearing here is in addition to the well-known one that comes from µ(t); see Eq. (5). A logarithmic deviation from scaling would have important implications for models of axion dark matter [57,63,65,66].…”