  The theory of massive photons in the presence of axions is studied as the
effective theory describing the electromagnetic response of semimetals when a
particular quartic fermionic pairing perturbation triggers the formation of
charged chiral condensates, giving rise to an axionic superconductor. We
investigate corrections to the Yukawa-like potential mediated by massive
photons due to axion excitations up to one-loop order and compute the
modifications of the London penetration length.
