(1) Max-Planck-Institut für Metallforschung, Institut für Physik, Heisenbergstr. 1, D-70569 Stuttgart, Germany;(2) Institut für Theoretische und Angewandte Physik, Universität Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
Abstract:
The hopping motion of charged light particles coupled to superconducting electrons as well as to phonons is investigated within the framework of a two-state model. Sufficiently far below the transition temperatureTc the hopping rate is dominated by one-phonon processes if the static energy shifts between the particle ground states are finite but smaller than twice the BCS energy gap. In the opposite limit of large energy asymmetries phonon coupling does not crucially influence the jump rates. The rôle of nonlinear lattice coupling is investigated.