Spontaneous symmetry breaking of an active magnetic fluid

We develop a continuum kinetic model for the dynamics of self-propelled micromagnets in a Newtonian fluid. Starting from a uniform random configuration, long-range interactions between magnetic dipoles lead to spontaneous symmetry breaking and unidirectional flow of the active suspension. By exploring the parameter space we investigate the order-to-disorder transition and obtain a phase diagram as a function of magnetic flux, number density, and diffusivity.