Affecting the structure of skyrmions using ferromagnetic nanodisks with inhomogeneous properties: switching skyrmion helicity and polarity

Abstract

The topological stability of skyrmions is an important element for using these objects in new technologies such as skyrmionics, spintronics, and so on. Indeed, this kind of stability keeps a skyrmion’s structure as unbending, shielding the information that, by chance, it could carry. On the other hand, a controlled manipulation of skyrmion configuration could be an extra ingredient for technological applications. It is not an easy task and, particularly, the control of skyrmion polarity and chirality (for Bloch-type) and helicity (for Néel-type) may be important in this direction. Here, we investigate the skyrmion oscillatory motion in a hybrid nanodisk by using atomistic spin dynamics simulations. If a skyrmion is made to oscillate in a disk formed by two different materials with opposite Dzyaloshinskii–Moriya interactions (), then its helicity experiences an inversion. Nonetheless, if the skyrmion oscillations occur in a homogeneous disk submitted to opposite magnetic fields in distinct regions (for instance, semi-disks 1 and 2), the skyrmion polarity and helicity suffer an inversion. Such skyrmionic-oscillators could provide a dynamical degree of freedom, yielding new functionalities to skyrmion-based logic devices.