Switching magnetic texture via in-plane magnetic field in noncentrosymmetric dipolar magnets: From skyrmions to antiskyrmions and nontopological magnetic bubbles

We theoretically investigate field-induced switching of magnetic topology in a nanodisk-shaped sample of noncentrosymmetric dipolar magnet in which the Dzyaloshinskii-Moriya interaction that stabilizes an antiskyrmion with $N_{\mathrm{s}\mathrm{k}}$=+1 and the magnetic dipole interaction that stabilizes a skyrmion with $N_{\mathrm{s}\mathrm{k}}$=$-1$ are in keen competition where $N_{\mathrm{s}\mathrm{k}}$ is the skyrmion number. Our micromagnetic simulations demonstrate that the competition offers a unique opportunity to switch magnetic textures with distinct magnetic topology among the antiskyrmion ($N_{\mathrm{s}\mathrm{k}}$=+1), elliptical skyrmion ($N_{\mathrm{s}\mathrm{k}}$=$-1$), and nontopological bubble ($N_{\mathrm{s}\mathrm{k}}$=0) in a deterministic manner by application of magnetic fields parallel to the sample plane. By calculating time and spatial profiles of energy contributions from respective interactions and magnetic anisotropy, we clarify the physical mechanism and properties of the observed field-induced topology switching phenomena. Our findings are expected to provide useful insights into the spintronic application of topological magnetism.