Speaker
Description
The Witten effect implies the electromagnetic interactions between axions and magnetic monopoles. Based on the quantum electromagnetodynamics, a generic low-energy axion-photon effective field theory was built by introducing two four-potentials ($A^\mu$ and $B^\mu$) to describe a photon. More anomalous axion-photon interactions and couplings ($g_{aAA}$, $g_{aBB}$ and $g_{aAB}$) arise in contrary to the ordinary axion coupling $g_{a\gamma\gamma}aF^{\mu\nu}\tilde{F}_{\mu\nu}$. As a consequence, the conventional axion Maxwell equations are further modified. We properly solve the new axion-modified Maxwell equations and obtain the axion-induced electromagnetic fields given a static electric or magnetic field. I will also mention our proposals of new search strategies to measure the new couplings for sub-$\mu$eV axion in haloscope experiments.
