7,583 research outputs found
Lane formation in a system of dipolar microswimmers
Using Brownian Dynamics (BD) simulations we investigate the non-equilibrium
structure formation of a two-dimensional (2D) binary system of dipolar colloids
propelling in opposite directions. Despite of a pronounced tendency for chain
formation, the system displays a transition towards a laned state reminiscent
of lane formation in systems with isotropic repulsive interactions. However,
the anisotropic dipolar interactions induce novel features: First, the lanes
have themselves a complex internal structure characterized by chains or
clusters. Second, laning occurs only in a window of interaction strengths. We
interprete our findings by a phase separation process and simple force balance
arguments
Novel structure formation of a phase separating colloidal fluid in a ratchet potential
Based on Dynamical Density Functional Theory (DDFT) we investigate a binary
mixture of interacting Brownian particles driven over a substrate via a
one-dimensional ratchet potential. The particles are modeled as soft spheres
where one component carries a classical Heisenberg spin. In the absence of a
substrate field, the system undergoes a first-order fluid-fluid demixing
transition driven by the spin-spin interaction. We demonstrate that the
interplay between the intrinsic spinodal decomposition and time-dependent
external forces leads to a novel dynamical instability where stripes against
the symmetry of the external potential form. This structural transition is
observed for a broad range of parameters related to the ratchet potential.
Moreover, we find intriguing effects for the particle transport.Comment: 6 pages, 4 figure
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