Phonon assisted tunneling in Josephson junctions
  The expression for additional subgap current in the presence of electron-phonon interaction is derived. We show that the phonon assisted tunneling leads to appearance of peaks on current-voltage characteristics at the Josephson frequencies corresponding to the Raman-active phonons. The relation of the obtained results to experimental observations are discussed. 
E. G. Maksimov, P. I. Arseyev and N. S. Maslova