Friction, order, and transverse pinning of a two-dimensional elastic lattice under periodic and impurity potentials

Frictional phenomena of two-dimensional elastic lattices are studied numeri cally based on a two-dimensional Frenkel-Kontorova model with impurities. I t is shown that impurities can assist the depinning. We also investigate an isotropic ordering and transverse pinning effects of sliding lattices, whic h are characteristic of the moving Bragg glass state and/or transverse glas s state. Peculiar velocity dependence of the transverse pinning is observed in the presence of both periodic and random potentials and discussed in th e relation with growing order and discommensurate structures.