  From a theoretical perspective, we demonstrate that nanometric magnetic
skyrmions are created by application of a circularly polarized microwave
magnetic field to a thin-plate Dzyaloshinskii-Moriya ferromagnet with
fabricated rectangular holes. This phenomenon is caused by an effective steady
magnetic field perpendicular to the microwave-polarization plane induced by the
rotating magnetic field and the intense interference of spin waves excited by
this magnetic field due to the hole structure, which causes reversals of local
magnetizations and results in the formation of skyrmions. Our proposal provides
a new option to write or create magnetic textures the sizes of which are much
smaller than the spot size of the external stimulus such as magnetic field,
light, and microwave.
