Axion detection via topological Casimir effect

Abstract

We propose a new table-top experimental configuration for the direct detection of dark matter QCD axions in the traditional open mass window 10-6 eVma10-2 eV using nonperturbative effects in a system with nontrivial spatial topology. Different from most experimental setups found in literature on direct dark matter axion detection, which relies on θ or →θ, we found that our system is in principle sensitive to a static θ≥10-14 and can also be used to set limit on the fundamental constant θQED which becomes the fundamental observable parameter of the Maxwell system if some conditions are met. Furthermore, the proposed experiments can probe entire open mass window 10-6 eVma10-2 eV with the same design, which should be contrasted with conventional cavity-type experiments being sensitive to a specific axion mass. Connection with Witten effect when the induced electric charge e′ is proportional to θ and the magnetic monopole becomes the dyon with nonvanishing e′=-eθ2π is also discussed.