Fluctuation-induced nucleation and dynamics of kinks on dislocation: Soliton and oscillation regimes in the two-dimensional Frenkel-Kontorova model

Numerical simulation of the dislocation motion in two-dimensional Frenkel-Kontorova model in the thermostat shows an unusual dynamical behavior. It appears that "kink" regime of dislocation gliding takes place in a certain region of parameters of the model but, in disagreement with the common views about the dislocation motion under plastic deformation condition, the kinks appear to be similar to sine-Gordon solitons despite the discreteness of the lattice, damping, and thermal fluctuations. At high enough stresses and temperatures the motion of the dislocation is accompanied by its oscillations rather than kink nucleation. [S0163-1829(99)02125-6].