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.
*This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No. DE-SC0016424 and as part of the Spins and Heat in Nanoscale Electronic Systems (SHINES) an Energy Frontier Research Center funded by U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No. DE-SC0012670.
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Presenters
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Yizhou Liu
- Electrical and Computer Engineering, University of California, Riverside
- Department of Electrical and Computer Engineering, University of California, Riverside