• Magnetic Bits by Electric Fields

    Controlled deleting (left) and writing (right) of individual nanoscale magnetic skyrmions by local electric fields. Between the individual images the tip of a scanning tunneling microscope was properly positioned and the local electric field was raised for a short time up to +3 V/nm (left) or -3V/nm (right). A single atomic vacancy in the ultrathin iron film (dark contrast) indicates the extremely small scale of the written and deleted skyrmions (bright contrast). P.-J. Hsu und R. Wiesendanger, University of Hamburg, Germany

    Researchers now make use of local electric fields for writing and deleting individual nanoscale magnetic skyrmions. Physicists of the University of Hamburg in Germany have demonstrated for the first time the controlled writing and deleting of individual nanoscale magnetic knots – so called skyrmions – by applying local electric fields to an ultrathin film of iron as data storage medium. These tiny knots in the magnetization of ultrathin metallic films exhibit an exceptional stability and are highly promising candidates for future ultra-high density magnetic recording. So far, they could be manipulated by local spin-currents and magnetic fields only. Now the research group at the University of Hamburg, headed by Roland Wiesendanger, report on the first electric-field controlled manipulation of nanoscale magnetic skyrmions in the journal Nature Nanotechnology (online issue of November 7, 2016).

  • Three-dimensional Structure of Skyrmions Becomes Visible for the First Time

    Three-dimensional structure of skyrmions. (c) Max Planck Institute for Intelligent Systems.

    Skyrmions are three-dimensional structures that occur in magnetic materials. They are magnetic vortices a few nanometers in size in which atomic elementary magnets are arranged in closed vortex structures. Skyrmions are topologically protected, meaning that their shape cannot be changed. First described in the 1950s by the mathematician Tony Skyrme, their three-dimensional structure is less than one hundred nanometers in size. It was thus not possible to make the structure visible – until now.