Skyrmions – small whirls in the magnetisation of magnetic materials – can have a diameter of less than 100nm. They may be important for the future of magnetic data storage and information processing if they can be moved rapidly and reliably along nanowires or other structures.
According to the researchers, skyrmions have only been created previously using expensive equipment and at temperatures as low as 5K.
"Our method is the simplest way to generate skyrmion bubbles thus far," said Argonne postdoctoral researcher Wanjun Jiang.
The team used a geometric structure to 'blow' the bubbles into shape in a very thin film. Using the facilities at Argonne's Center for Nanoscale Materials, the team built a constricted wire out of a three layered structure in which a layer of magnetic material is sandwiched between layers of tantalum and tantalum oxide.
Long stripes of magnetic domains appear in the magnetic material on one side of a tiny channel. When an electric current was applied to the metal layers, the stripes stretched through the channel and broke into skyrmions on the other side. By applying a smaller electric current through the system, the skyrmions could be moved.
"We think this method could apply to many more materials," Jiang added. "This opens many new opportunities for the future."
