  A skyrmion in a nanosized disk of a chiral magnet can be used as a bit of
information. To this end, it is desirable to control the creation and removal
of a skyrmion only by currents without using external magnetic fields. Here we
propose to create a skyrmion by applying a current pulse to a nanodisk. The
skyrmion can be removed from the disk by applying a dc current. We show that
the dynamics of the created skyrmion can lead to a rectification effect, in
which a dc voltage is generated by the motion of skyrmion in the presence of an
ac current.
