Antiskyrmionic ferroelectric medium

Magnetization knots, known as ferromagnetic skyrmions, are string-like nanoobjects with a vortex-like spin texture. By now they have been found in many chiral ferromagnets. At the same time, there is only one material known to form geometrically equivalent vortices of ferroelectric polarization, the crystal of lead titanate. Our density functional theory based atomistic simulations now reveal that in a related material barium titanate, intrinsic string-like vortexes of another type are stable instead of skyrmions - ferroelectric antiskyrmions. They remind ring windings of decorative knots, have just 2-3 nm in diameter, possess a hexagonal section and an exotic topological charge of minus two. These findings suggest that ferroelectrics might in principle serve as memory media operating with nanoscale topological line defects and that they could be antiskyrmion forming media rather than skyrmion media.