  To exploit nanometric magnetic skyrmions as information carriers in
high-density storage devices, a method is needed that creates intended number
of skyrmions at specified places in the device preferably at a low energy cost.
We theoretically propose that using a system with a fabricated hole or notch,
the controlled creation of individual skyrmions can be achieved even when using
an external magnetic field applied to the entire specimen. The fabricated
defect turns out to work like a catalyst to reduce the energy barrier for the
skyrmion creation.
