  We examined the lane formation dynamics of oppositely self-driven binary
particles by molecular dynamics simulations of a two-dimensional system. Our
study comprehensively revealed the effects of the density and system size on
the lane formation. The phase diagram distinguishing the no-lane and lane
states was systematically determined for various combinations of the
anisotropic friction coefficient and the desired velocity. A peculiar clustered
structure was observed when the lane was destroyed by greatly increasing the
desired velocity. A strong system size effect was demonstrated by the
relationship between the temporal and spatial scales of the lane structure.
This system size effect can be attributed to an analogy with the driven lattice
gas. The transport efficiency was characterized from the scaling relation in
terms of the degree of lane formation and the interface thickness between
different lanes.
