Multiferroic skyrmions in BiFeO3

We show here using atomistic simulations that ${\mathrm{BiFeO}}_{3}$ films can be driven through a topological transition when increasing uniaxial anisotropy, which can possibly be achieved by strain. Tuning the anisotropy close to the transition, we show that individual antiferromagnetic skyrmions can reach a very large topological protection. These entities can then be excited by electric fields and spin torque and controllably driven at speeds exceeding 10 km/s.