Ultrafast switching of the electric polarization and magnetic chirality   in BiFeO3 by an electric field
  Using a first-principles-based effective Hamiltonians within molecular dynamics simulations, we discover that applying an electric field that is opposite to the initial direction of the polarization results in a switching of both the polarization and the magnetic chirality vector of multiferroic BiFeO3 at an ultrafast pace (namely of the order of picoseconds). We discuss the origin of such a double ultrafast switching, which is found to involve original intermediate magnetic states and may hold promise for designing various devices. 
Satadeep Bhattacharjee, Dovran Rahmedov, Dawei Wang, Jorge Iniguez and   Laurent Bellaiche
cond-mat.mtrl-sci