Spin wave modes in a cylindrical nanowire in crossover dipolar-exchange regime

TL;DR

This paper investigates the spin wave modes in a cylindrical Ni nanowire, exploring their dispersion, mode interactions, and tunability under magnetic fields using semi-analytical and numerical methods.

Contribution

It provides a detailed analysis of spin wave dynamics in nanowires considering both magnetostatic and exchange interactions, including mode crossing and field effects.

Findings

Identification of dispersion branches and mode crossing behavior.

Demonstration of spectrum tuning via external magnetic field.

Insights into the interplay of dipolar and exchange interactions.

Abstract

Nanoscale magnetic systems have been studied extensively in various geometries, such as wires of different cross-sections, arrays of wires, dots, rings, etc. Such systems have interesting physical properties and promising applications in advanced magnetic devices. Uniform magnetic nanowires are the basic structures which were broadly investigated. However, some of their dynamical properties, like: (anti)crossing between the spin wave modes and impact of the magnetic field on spin wave spectrum, still need to be exploited. We continue this research by investigation of the spin wave dynamics in solid Ni nanowire of the circular cross-section. We use two approaches: semi-analytical calculations and numerical computations based on finite element method. We solve coupled Landau-Lifshitz and Maxwell equations and consider both magnetostatic and exchange interactions. We identify the dispersion brunches and its (anti)crossing by plotting the spatial profiles of spin wave amplitudes and magnetostatic potential. We also check how we can tune the spectrum of the modes by application of the external magnetic field and how it affects the modes and their dominating type of interaction.