Binding a Hopfion in Chiral Magnet Nanodisk

ORAL

Abstract

Hopfions are three-dimensional topological textures characterized by the integer Hopf invariant $Q_H$. Here, we present the realization of a zero-field, stable hopfion spin texture in a magnetic system consisting of a chiral magnet nanodisk sandwiched by two films with perpendicular magnetic anisotropy. The preimages of the spin texture and numerical calculations of $Q_H$ show that the hopfion has $Q_H=1$. Furthermore, another non-trivial state that includes a monopole--antimonopole pair (MAP) is also stabilized in this system. By applying an external magnetic field, hopfion and MAP states with the same polarization can be switched between each other. The topological transition between the hopfion and the MAP state involves a creation (annihilation) of the MAP and twist of the preimages. Our work paves the way to study non-trivial 3D topological spin textures and stimulates more investigations in the field of 3D spintronics.

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Presenters

  • Yizhou Liu

    Electrical and Computer Engineering, University of California, Riverside, Department of Electrical and Computer Engineering, University of California, Riverside

Authors

  • Yizhou Liu

    Electrical and Computer Engineering, University of California, Riverside, Department of Electrical and Computer Engineering, University of California, Riverside

  • Roger Lake

    Electrical and Computer Engineering, University of California, Riverside, University of California, Riverside, Department of Electrical and Computer Engineering, University of California, Riverside

  • Jiadong Zang

    Department of Physics, University of New Hampshire, University of New Hampshire, Department of Physics and Materials Science Program, University of New Hampshire, Physics, University of New Hampshire