Stable magnetic monopoles in spinor polariton condensates

We consider half-integer topological defects in a spinor Bose-Einstein condensate of exciton polaritons. We show that they accelerate under the effect of an in-plane effective magnetic field, like regular electric charges in the electric field. The trajectories of these analogs of magnetic monopoles are derived analytically and checked by numerical simulations. We show that these ``magnetic charges'' propagate at large in-plane velocities and remain stable up to a critical magnetic field, thanks to the unique spin anisotropy of polariton interactions.