  In this paper, interstitial migration generated by scattering with a mobile
breather is investigated numerically in a Frenkel-Kontorova one-dimensional
lattice. Consistent with experimental results it is shown that interstitial
diffusion is more likely and faster than vacancy diffusion. Our simulations
support the hypothesis that a long-range energy transport mechanism involving
moving nonlinear vibrational excitations may significantly enhance the mobility
of point defects in a crystal lattice.
