Control and manipulation of a magnetic skyrmionium in nanostructures Article Swipe
YOU?
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· 2016
· Open Access
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· DOI: https://doi.org/10.1103/physrevb.94.094420
· OA: W2336366999
A magnetic skyrmionium is a nontopological soliton, which has a doughnut-like\nout-of-plane spin texture in thin films, and can be phenomenologically viewed\nas a coalition of two topological magnetic skyrmions with opposite topological\nnumbers. Due to its zero topological number ($Q=0$) and doughnut-like\nstructure, the skyrmionium has its distinctive characteristics as compared to\nthe skyrmion with $Q=\\pm 1$. Here we systematically study the generation,\nmanipulation and motion of a skyrmionium in ultrathin magnetic nanostructures\nby applying a magnetic field or a spin-polarized current. It is found that the\nskyrmionium moves faster than the skyrmion when they are driven by the\nout-of-plane current, and their velocity difference is proportional to the\ndriving force. However, the skyrmionium and skyrmion exhibit an identical\ncurrent-velocity relation when they are driven by the in-plane current. It is\nalso found that a moving skyrmionium is less deformed in the current-in-plane\ngeometry compared with the skyrmionum in the current-perpendicular-to-plane\ngeometry. Furthermore we demonstrate the transformation of a skyrmionium with\n$Q=0$ into two skyrmions with $Q=+1$ in a nanotrack driven by a spin-polarized\ncurrent, which can be seen as the unzipping process of a skyrmionium. We\nillustrate the energy and spin structure variations during the skyrmionium\nunzipping process, where linear relations between the spin structure and\nenergies are found. These results could have technological implications in the\nemerging field of skyrmionics.\n
