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The behavior of interacting active disks trapped by two planar hard walls is investigated. Motivated by earlier works, we employed active dynamics simulation in order to investigate the emergence of lanes of particles and their internal structure. Further we observed a correlation between the number of lanes formed and channel width. At first sight, larger channels favor the emergence of lanes with fluid-like bulk structure among them. We saw that, for a given packing fraction and wall separation, one realizes a better structural organization, very close to a triangular lattice, which was absent for other cases. We attributed the crystallization in the bulk to the repulsion from upper and bottom particles attached to the walls. The fluctuation of the total number of particles at the walls also is analyzed and its contribution for the lane formation and structure is considered.

We study, numerically, a system of active particles with either a single noise value or a mixture of equal proportions of particles with two noise values under the influence of an attractive periodic background potential, and we observe their diffusion regimes and trapping states. For the single noise system, we show that the slow diffusion is correlated to a significant particle trapping, while normal diffusion is seen for partial or no trapping. Our results indicate that low noise particles are less susceptible to the background, i.e., they have a smaller chance to be trapped as compared to higher noise particles for the same background, and that denser systems achieve a no-trapping state, unless for the largest noise value we studied. For the mixtures, we study the sorting of particles based on their noise value differences and observe that particles with distinct noises are trapped at distinct radii compared to a trap minimum, and, since these radii depend on the density, the latter should be well tuned in order to have an efficient sorting.

In this work we studied the diffusive behavior of active brownian particles under lateral parabolic confinement. The results showed that we go from subdiffusion to ballistic motion as we vary the angular noise strength and confinement intensity. We argued that the subdiffusion regimes appear as consequence of the restricted space available for diffusion (achieved either through large confinement and/or large noise); we saw that when there are large confinement and noise intensity, a similar configuration to single file diffusion appears; on the other hand, normal and superdiffusive regimes may occur due to low noise (longer persistent motion), either through exploring a wider region around the potential minimum in the transverse direction (low confinement), or by forming independent clusters (high confinement)., 6 pages, 6 figures, accepted for publication in Physica A