The phase synchronization of an axion and a superconductor
  The effects of the axion field have been widely studied in theoretical physics, particularly in particle physics. Considering the phase synchronization and the mean free path of the axion, the bulk of the phase coherent superconductor is regarded as the weak link region of the Josephson junction.It is expected that the axion mass influences the London penetration depth.There is a slight possibility of detecting this effect because the effect becomes more significant in superconductor with a low carrier density $n_s$.The differences due to the choice of axion model and the axion mass are discussed. 
Hideto Manjo and Koichiro Kobayashi and Kiyoshi Shiraishi
cond-mat.supr-con hep-ph