Phase separation in magnetic chiral fluids

Phase separation in active particle systems and the spatio-temporal organization of chiral

fluids are two prominent research areas of continuous interest. I will describe the collectively self-organiztion of spinning ferromagnetic rotors  that interact both via hydrodynamic

and dipolar forces into  circulating clusters, At   high spinning frequency, hydrodynamics dominate over attractive magnetic interactions and impede

coarsening,. A  minimal numerical model brings insight into  the fundamental role of

hydrodynamics and of the boundary plane in the organization process. These results highlight  the importance of fluid mediated long range interactions in the assembly of active spinning materials.