Vortex-chirality-dependent standing spin-wave modes in soft magnetic nanotubes

This is the authors' abstract. We don't add key points for this paper.

Spin-wave (SW) modes excited in cylindrical nanotubes of finite length were investigated using finite-element micromagnetic simulations. From the simulation results along with the relevant analytical interpretation, we found unique dynamic modes representative of a variety of standing SW modes. Those modes are controllable not only according to the geometric confinements of given nanotubes but also by the relative configuration of the vortex-chirality at both ends of the nanotubes. The asymmetric (symmetric) spin-wave dispersion originates from nonreciprocal (reciprocal) spin-wave propagations from the parallel (antiparallel) configuration of vortex chiralities at both ends of the nanotubes. Using a simple analytical model, we estimated the quantized dispersions of the excited modes that agree with the simulation results. This work facilitates further understanding of discrete standing SW modes in three-dimensional curvilinear nano-elements, such as cylindrical nanotubes, and opens up a broader and deeper perspective on chirality-dependent SW modes.