Diameter-Controlled High-Order Vortex States and Magnon Hybridization in Nanotubes
Phys. Rev. Lett. 136, 096703 – Published 4 March, 2026
DOI: https://doi.org/10.1103/jr3h-1674
Abstract
Curved magnets offer a rich phase diagram and hold great promise for next-generation spintronic technologies. This Letter establishes the paramount significance of high-order vortex states (e.g., with winding number ) in nanotubes, which uniquely enable magnonic functionalities fundamentally inaccessible to conventional magnetic systems, and additionally, the superposition of high-order vortex and helical states is identified. These states arise from diameter-dependent competition between the nearest-neighbor ferromagnetic () and longer-range antiferromagnetic () couplings, as jointly validated through density-functional theory calculations and Heisenberg modeling of phase diagrams. Based on the Landau-Lifshitz-Gilbert equation, we show that vortex states exhibit orbital angular momentum (OAM) hybridization governed by selection rules: magnetic anisotropy energy (MAE) and an external magnetic field couple the mode to and , respectively. For the state, MAE couples the mode with , producing eight-petal magnon density patterns and providing a natural mechanism for generating high-OAM magnons. These findings establish a predictive theoretical framework for controlling high-order vortex states in curved magnets and highlight nanotubes as a promising platform for exploring complex magnetism and for the development of future magnonic and spintronic devices.