  By performing numerical simulations for the handwritten digit recognition
task, we demonstrate that a magnetic skyrmion lattice confined in a thin-plate
magnet possesses high capability of reservoir computing. We obtain a high
recognition rate of more than 88%, higher by about 10% than a baseline taken as
the echo state network model. We find that this excellent performance arises
from enhanced nonlinearity in the transformation which maps the input data onto
an information space with higher dimensions, carried by interferences of spin
waves in the skyrmion lattice. Because the skyrmions require only application
of static magnetic field instead of nanofabrication for their creation in
contrast to other spintronics reservoirs, our result consolidates the high
potential of skyrmions for application to reservoir computing devices.
