  Magnetic hopfion is three-dimensional (3D) topological soliton with novel
spin structure that would enable exotic dynamics. Here we study the current
driven 3D dynamics of a magnetic hopfion with unit Hopf index in a frustrated
magnet. Attributed to spin Berry phase and symmetry of the hopfion, the phase
space entangles multiple collective coordinates, thus the hopfion exhibits rich
dynamics including longitudinal motion along the current direction, transverse
motion perpendicular to the current direction, rotational motion and dilation.
Furthermore, the characteristics of hopfion dynamics is determined by the ratio
between the non-adiabatic spin transfer torque parameter and the damping
parameter. Such peculiar 3D dynamics of magnetic hopfion could shed light on
understanding the universal physics of hopfions in different systems and boost
the prosperous development of 3D spintronics.
