Three layers of skyrmions in the magnetic triple-layer structure without the Dzyaloshinsky-Moriya interaction

The skyrmionic state is an exciting realm of study and the skyrmions are being explored as the promising candidates of information carriers. In most systems, the skyrmions originate from the Dzyaloshinsky–Moriya interaction (DMI). However, in this work, it is demonstrated that in the triple-layer CoPt/Co/CoPt structure, the skyrmion-like state can be formed not only in the CoPt layers but also in the middle Co layer, without DMI. In this new structure, the skyrmion-like state in Co layer can exist in a large CoPt thickness range with thick Co. It can be very stable even against the external field from −500 to 200 mT along Z axis. The skyrmion number (S) in Co (SCo) can be as large as 0.9. These advanced properties make it high application potential for the future information-processing and storage devices.