Details

Autor(en) / Beteiligte

• Gallardo, R A
• Alvarado-Seguel, P
• Schneider, T
• Gonzalez-Fuentes, C
• Roldán-Molina, A
• Lenz, K
• Lindner, J
• Landeros, P

Titel

Spin-wave non-reciprocity in magnetization-graded ferromagnetic films

Ist Teil von

• New journal of physics, 2019-03, Vol.21 (3), p.33026

Ort / Verlag

Bristol: IOP Publishing

Erscheinungsjahr

2019

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• A theoretical approach has been developed to study the spin-wave dynamics of magnetization-graded ferromagnetic films, where the magnetic properties change along the film thickness. The theory is based on a multilayer approach, where the influence of both long-range dipolar interactions and interlayer exchange coupling between sublayers is included. This allows for instance to describe films with a continuous variation of the saturation magnetization along the thickness. A systematic study is carried out in order to analyze different profiles of the saturation magnetization, which is checked through a test of convergence. It is found that the spin-wave dispersion is significantly modified when the strength of the magnetization changes in the bulk film, where a notable frequency non-reciprocity of two counter propagating spin waves is predicted. This is associated with heterosymmetric mode profiles and a modification of the conventional quantization condition associated to perpendicular standing spin-wave modes. Micromagnetic simulations have been carried out to validate the model, where a perfect agreement is reached between both methods. These results show that magnetization-graded ferromagnetic films can be used to channel and control spin waves, thus promoting different kinds of functionalities for magnon-based devices.