  Transverse depinning dynamics of a periodic-square-substrate modulated
two-dimensional dusty plasma solid driven by a constant force in the
longitudinal direction are investigated using Langevin dynamical simulations.
During the increase of the commensuration ratio (the number ratio of particles
to substrate potential wells), the nonmonotonic variation trend of the critical
transverse depinning force is observed. It is found that the local maxima and
minima of the critical transverse depinning force just correspond to the
dynamical commensurate and incommensurate conditions, respectively. The
dynamical commensurate effect is also clearly exhibited from the stable
one-dimensional channel particle trajectories and the highly ordered structure,
however, both the particle trajectories and the structure are more disordered
under the incommensurate conditions. The nonmonotonic variation of the critical
transverse depinning force is attributed to the stability of the lattice
structure under various commensuration ratios.
