  We report two-dimensional discrete dislocation dynamics simulations of
combined dislocation glide and climb leading to `power-law' creep in a model
aluminum crystal. The approach fully accounts for matter transport due to
vacancy diffusion and its coupling with dislocation motion. The existence of
quasi-equilibrium or jammed states under the applied creep stresses enables
observations of diffusion and climb over time scales relevant to power-law
creep. The predictions for the creep rates and stress exponents fall within
experimental ranges, indicating that the underlying physics is well captured.
