Merging of spin-wave modes in obliquely magnetized circular nanodots
Authors: Julia Kharlan, Vladyslav Borynskyi, Sergey A. Bunyaev, Pavlo Bondarenko, Olga Salyuk, Vladimir Golub, Alexander A. Serga, Oleksandr V. Dobrovolskiy, Andrii Chumak, Roman Verba, and Gleb N. Kakazei
Phys. Rev. B 105, 014407
Abstract: Magnetic nanoelements attract great interest due to their prospects for data storage and signal processing. Spin-wave confinement in these elements implies wave-number quantization, discrete frequency spectra and thus complex resonance patterns, strongly dependent on the elements’ geometry and static magnetic configuration. Here we report experimental observation of unconventional single-frequency resonance response of flat circular Permalloy nanodots, which is achieved via the application of a magnetic field at a certain critical angle ˜θB with respect to the dot normal. This observation is explained as the merging of spin-wave eigenmodes under the transition of the spin-wave dispersion from the forward-volume to the backward-volume type, as elucidated by micromagnetic simulations in conjunction with an analytical theory. Our results offer a way for the creation of spin-wave systems with spectrally narrow magnetic noise.