arXiv subjects

Dongyi Yang

Publications and source records attributed to Dongyi Yang.

3 recordsLinked to original sources

arXiv2026

Collective response and noise of a levitated ferromagnet lattice for ultralight dark matter detection

Ultralight dark matter can induce weak oscillating magnetic-like signals and can therefore be searched for with precision magnetometry. Levitated ferromagnets provide a sensitive platform for such searches, but a single ferromagnet is limited in total polarized spin and readout performance. We investigate a levitated ferromagnet lattice as a scalable detector for ultralight dark matter. We develop a theoretical description of the collective lattice response in the fully trapped regime, incorporating dipole-dipole interactions, finite-size effects, and boundary-induced mode mixing. We further analyze the collective noise budget and show that interaction effects mainly produce a narrow blind zone through thermal-noise amplification, while away from this region, the lattice preserves favorable collective noise scaling. We then derive projected sensitivities to axion-electron, dark-photon, and axion-photon couplings. We find that the lattice improves the reach in all three channels relative to a single-ferromagnet detector, with an additional coherent signal enhancement in the axion-photon channel from the lattice-generated electromagnetic background.

hep-ph↗

arXiv2026

Ultralight Dark Matter Detection with a Ferromagnet Lattice

A levitated ferromagnet provides an exceptionally sensitive probe of ultralight dark matter (ULDM) through measuring weak magnetic-like field signals. We propose a ferromagnet lattice magnetometer that coherently combines multiple levitated ferromagnets to enhance effective sensitivity. By replacing a single ferromagnet with a lattice, we increase the total polarized spin while preserving the intrinsic dynamical response of each constituent ferromagnet. We show that magnetic dipole-dipole interactions within the lattice can be dynamically suppressed through a high-frequency magnetic field, rendering the system effectively noninteracting, at the cost of only a moderate reduction in signal amplitude due to the distinct renormalization of linear and quadratic spin responses. We analyze the noise properties of the lattice and demonstrate that collective readout leads to favorable scaling with the number of ferromagnets. Interpreted in terms of axion-electron, dark photon, and axion-photon couplings, our results yield projected sensitivities that significantly exceed existing single-ferromagnet implementations. In particular, for axion-photon interactions, we find a nontrivial lattice-induced enhancement of the signal itself, leading to sensitivities that surpass existing constraints over a broad mass range.

hep-ph↗

arXiv2025

Constraints on Axion Dark Matter by Spin-Dependent Macroscopic Force

Axion-like particles (ALPs) are hypothetical particles that serve as promising candidates for cold dark matter. Portals like inelastic axion scattering and axion propagated force have been employed to search for the upper limit of the ALPs' coupling with standard model particles. Other methods, like the axion-fermion interaction in the CASPEr experiment, integrate the dark matter motion into the measurement. We suggest a new method for detecting dark matter axions based on axionelectron elastic scattering. In the pseudoscalar axion model, this interaction can be seen as an effective magnetic field, so high-sensitivity atomic magnetometers can be utilized to measure this interaction. The scattering cross section of this process is significantly amplified by the high number density and occupation number of axion dark matter. The upper limit of the electron-axion coupling coefficient obtained from this process can reach two orders of magnitude higher than previous results at low axion mass, and will exceed the astrophysics limits by using a developing magnetometer. This scattering process also provides an efficient way to detect local structures of dark matter.

hep-ph↗