Sensitivity of two-mode SRF cavity to generic electromagnetism of sub-$\mu$eV dark matter

Abstract

The low-mass dark matter (DM) such as axion or wavelike scalar is a plausible DM candidate. Recently, the possible non-standard couplings of low-mass DM has drawn much attention. In this work we investigate the detection of electromagnetic couplings in a few benchmark models of low-mass DM. For illustration, we consider the generic axion electrodynamics including CP violating coupling as well as the newly proposed axion electromagnetodynamics. The superconducting radio frequency (SRF) cavity with two modes has more advantages than the traditional cavity approach with static background field. We utilize the two-mode SRF cavity to probe the generic couplings of low-mass DM with frequency lower than GHz. We show the sensitivity of the SRF cavity to the axion couplings in the above frameworks.