Driven dynamics of a two-dimensional incommensurate interface

Abstract

Sliding dynamics of a two-dimensional incommensurate lattice on a substrate lattice with a periodic potential is studied using numerical simulations. This lattice system is a simplified model of nanoscale experimental devices such as the friction force microscope and the surface force apparatus. In the present system, when a misfit angle between the principal directions of lattices exists and the interatomic interaction between lattices is strong, the lattice is pinned and its structure is modulated complicatedly. Even in sliding states the effect of the modulation is highly affected, and the sliding of the lattice takes place in a certain direction which may not be parallel to the direction of the external driving force. This is due to the formation of flow channels accompanied by confining barriers in the transverse direction to the sliding motion. The directions of flow channels obviously reflect the pinned lattice structures in the stationary state. In such sliding states pinning behavior in the direction transverse to the flow channels is observed.