Compositional Interfaces Reshape Spin-Wave Spectra in Nanowires Without Changing Geometry

Micromagnetic simulations demonstrate that longitudinal compositional interfaces reshape the equilibrium magnetic configurations and spin-wave dynamics of homogeneous and multisegmented nanowires. Reported by researchers Felipe Sarria, Eduardo Saavedra, Alejandro Pereira, and Juan Escrig in the journal Scientific Reports, the investigation reveals that tailoring the longitudinal distribution of magnetic material parameters modifies the spin-wave resonance spectrum without changing the external nanowire geometry. This computational approach directly addresses a central challenge in magnonics, where engineering spin-wave spectra has remained difficult without modifying device geometry.

The investigation focused specifically on homogeneous and multisegmented nanowires incorporating cobalt, nickel, and cobalt-nickel (Co/CoNi/Ni) material segments. Through detailed micromagnetic simulations, the authors examined how longitudinal compositional interfaces influence internal magnetic properties across the different structures. The simulation results show that the longitudinal compositional architecture modifies the magnetic energy landscape of the nanowires. This altered magnetic energy landscape gives rise to distinct equilibrium magnetization textures and produces substantial changes in the spatial distribution of spin-wave excitations throughout the investigated nanowire architectures.

To evaluate the dynamic behavior of the nanostructures, the authors calculated dynamic susceptibility spectra across all investigated homogeneous and multisegmented configurations. These numerical calculations revealed substantial changes in both resonance frequencies and spectral amplitudes across the different architectural designs.

A central outcome of the dynamic susceptibility analysis is the distinct microwave band behavior observed between the homogeneous and multisegmented nanowires. Homogeneous nickel nanowires exhibited dominant resonances located in the C microwave band, whereas homogeneous cobalt nanowires displayed dominant resonances in the Ku microwave band. In contrast, several multisegmented configurations displayed their strongest dynamic response within the technologically relevant X microwave band.

The authors conclude that these results offer a foundational basis for the future design and development of compositionally engineered magnonic nanostructures.

Subject of Research: Spin-wave dynamics in compositionally engineered nanowires

Article Title: Engineering spin-wave spectra through longitudinal compositional interfaces

Article References: Sarria, F., Saavedra, E., Pereira, A., & Escrig, J. (2026). Engineering spin-wave spectra through longitudinal compositional interfaces. Scientific Reports. https://doi.org/10.1038/s41598-026-80650-7

Image Credits: AI Generated

DOI: 10.1038/s41598-026-80650-7

Keywords: magnonics, spin waves, micromagnetic simulations, nanowires, compositional interfaces, dynamic susceptibility, resonance frequencies, spectral amplitudes, magnetization textures, magnetic energy landscape, cobalt nanowires, nickel nanowires, multisegmented nanowires, C microwave band, Ku microwave band, X microwave band, Co/CoNi/Ni nanowires, magnonic nanostructures