Axion Quasiparticles for Axion Dark Matter Detection

TL;DR

This paper proposes using antiferromagnetic topological insulators with axion quasiparticles to detect axion dark matter by converting it into measurable THz photons, leveraging resonance and tunability via magnetic fields.

Contribution

It introduces a novel detection method utilizing axion quasiparticles in topological insulators, including detailed modeling of losses and resonance conditions for axion-to-photon conversion.

Findings

Resonant conversion of axion DM into THz photons demonstrated

Transmission spectroscopy can measure axion quasiparticle properties

Detection feasible for axion masses between 1 and 10 meV

Abstract

It has been suggested that certain antiferromagnetic topological insulators contain axion quasiparticles (AQs), and that such materials could be used to detect axion dark matter (DM). The AQ is a longitudinal antiferromagnetic spin fluctuation coupled to the electromagnetic Chern-Simons term, which, in the presence of an applied magnetic field, leads to mass mixing between the AQ and the electric field. The electromagnetic boundary conditions and transmission and reflection coefficients are computed. A model for including losses into this system is presented, and the resulting linewidth is computed. It is shown how transmission spectroscopy can be used to measure the resonant frequencies and damping coefficients of the material, and demonstrate conclusively the existence of the AQ. The dispersion relation and boundary conditions permit resonant conversion of axion DM into THz photons in a material volume that is independent of the resonant frequency, which is tuneable via an applied magnetic field. A parameter study for axion DM detection is performed, computing boost amplitudes and bandwidths using realistic material properties including loss. The proposal could allow for detection of axion DM in the mass range between 1 and 10 meV using current and near future technology.