Skyrmions in functional materials

Skyrmions are topological spin defects which have been observed in chiral magnets and other materials including some multiferroics in recent years. The typical size of a skyrmion varies in the range 5-100 nm with thousands of spins in it and a characteristic energy scale of 1 meV per layer. They can also be viewed as emergent mesoscopic particles which can be moved or manipulated by electrical current, temperature gradient, electric and magnetic field, thus rendering them useful for a variety of applications including information storage. In particular, the current needed to move a skyrmion is five to six orders of magnitude smaller than that needed for moving magnetic domain walls and vortices, therefore making them promising candidates for spintronics.