Controlled nucleation of hopfions with field pulses

We demonstrate a mechanism for the deterministic nucleation of magnetic hopfions in cylindrical nanopillars via transient magnetic field pulses. By exploiting a chiral magnetic cylinder with engineered surface uniaxial anisotropy, we show that field pulses trigger a non-equilibrium magnetization dynamics. Depending on the pulse amplitude, the system relaxes into distinct topologically protected energy minima, stabilizing either isolated hopfions or coexisting states with other three-dimensional solitons. This approach offers a framework for manipulating 3D topological textures without requiring localized spin-polarized currents, broadening the understanding of three-dimensional nanomagnetism.