Fig. 3: Orientation distribution, polarization and fluxes.

A Orientation distribution of particles near the wall at activity Pe_s = 7. We consider in our ABP model (dotted lines) as well as in the experiment (purple solid line) the situation which corresponds to the left wall (x = 0) in Fig. 1E. Thus 0^∘ corresponds to a particle oriented away from the wall and 90^∘ is equivalent to a particle oriented against gravity. The numerical bulk distribution is also plotted in pink. B The numerical profiles of the z-component of the polarization (particle orientation) M_z/ρ in the adsorption layer (dashed lines) and in the bulk (dotted line) at Pe_s = 17 for the four cases: a neutral wall (blue), an adhesive wall (orange), an aligning wall (green) and a wall with alignment plus attraction (red). Particles point upwards if M_z > 0 and downwards if M_z < 0. C, D Numerical streamlines of a velocity field v = J/ρ together with the packing fraction field ϕ for a simultaneously attracting and aligning wall with \(\tilde{\epsilon }=0.25{{{{{{{{\rm{Pe}}}}}}}}}_{{{{{{{{\rm{s}}}}}}}}}=4.25\) and \(\tilde{\Gamma }=2{{{{{{{{\rm{Pe}}}}}}}}}_{{{{{{{{\rm{s}}}}}}}}}=34\) C and for a neutral wall D.