Structure, barriers and relaxation mechanisms of kinks in the 90-degree   partial dislocation in silicon
  Kink defects in the 90-degree partial dislocation in silicon are studied using a linear-scaling density-matrix technique. The asymmetric core reconstruction plays a crucial role, generating at least four distinct kink species as well as soliton defects. The energies and migration barriers of these entities are calculated and compared with experiment. As a result of certain low-energy kinks, a peculiar alternation of the core reconstruction is predicted. We find the solitons to be remarkably mobile even at very low temperature, and propose that they mediate the kink relaxation dynamics. 
R. W. Nunes, J. Bennetto, and David Vanderbilt (Department of Physics   and Astronomy - Rutgers University)