Microwave spectrum of square Permalloy dots: Quasisaturated state

Bailleul, Matthieu; Höllinger, Rainer; Fermon, C.

doi:10.1103/physrevb.73.104424

Cited by 72 publications

(87 citation statements)

References 40 publications

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“…This is in agreement with Ref. 17 in which the spin-wave well model was extended to account for the nonuniform static state magnetization. Here it is found that the FFT magnitude extends across regions of positive and negative internal fields, as seen in Fig.…”

Section: Field Dependencesupporting

confidence: 79%

“…In particular, we found that the observed behavior evokes that of spin-wave well modes observed in larger 3 m square Permalloy elements presented in Ref. 17. In Ref.…”

Section: Introductionmentioning

confidence: 83%

“…In Ref. 17 the authors show that a combination of both the equilibrium and in-plane dynamic dipolar internal fields give rise to the localization of modes in the transition region between high and low internal fields, away from which the mode amplitude decreases. A general feature of the results presented in this paper is the occurrence of a crossover from a quasiuniform excitation that occupies the majority of the element volume to a regime that is dominated by several modes weakly localized near the element edges that lie perpendicular to the bias field.…”

Section: Introductionmentioning

confidence: 99%

“…There have been many reports on the excitation of similar modes in micrometer sized elements. 11,12,14,17,20 In Ref. 24 the evolution of the mode character was studied for noninteracting nanoscale elements in which the static magnetization was assumed to be uniform.…”

Section: Introductionmentioning

confidence: 99%

“…For example, the nonuniform demagnetizing field may lead to the spatial confinement and quantization of spin-wave modes on the nanometer length scale. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] For thin-film elements where the magnetization lies in plane, the magnitude of the static in-plane demagnetizing field and the nonuniformity of the total effective field acting upon the magnetization increase when the element aspect ratio ͑size to thickness͒ is reduced. This results in a richer mode spectrum and hence in a less uniform magnetic response to a pulsed magnetic field, which can be directly imaged in the case of micrometer sized magnetic elements.…”

Section: Introductionmentioning

confidence: 99%

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Time-resolved investigation of magnetization dynamics of arrays of nonellipsoidal nanomagnets with nonuniform ground states

et al. 2008

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Time-resolved scanning Kerr microscopy measurements have been performed upon arrays of square ferromagnetic nanoelements of different sizes and for a range of bias fields. The experimental results were compared to micromagnetic simulations of model arrays in order to understand the nonuniform precessional dynamics within the elements. In the experimental spectra acquired from an element of length of 236 nm and thickness of 13.6 nm, two branches of excited modes were observed to coexist above a particular bias field. Below this so-called crossover field, the higher frequency branch was observed to vanish. Micromagnetic simulations and Fourier imaging revealed that modes from the higher frequency branch had large amplitude at the center of the element where the effective field was parallel to the bias field and the static magnetization. Modes from the lower frequency branch had large amplitude near the edges of the element perpendicular to the bias field. The simulations revealed significant canting of the static magnetization and effective field away from the direction of the bias field in the edge regions. For the smallest element sizes and/or at low bias field values, the effective field was found to become antiparallel to the static magnetization. The simulations revealed that the majority of the modes were delocalized with finite amplitude throughout the element while the spatial character of a mode was found to be correlated with the spatial variation in the total effective field and the static magnetization state. The simulations also revealed that the frequencies of the edge modes are strongly affected by the spatial distribution of the static magnetization state both within an element and within its nearest neighbors. Furthermore, the simulations suggest that collective modes may be supported in arrays of interacting nanomagnets, which act as magnonic crystals.

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Section: Field Dependencesupporting

confidence: 79%

“…In particular, we found that the observed behavior evokes that of spin-wave well modes observed in larger 3 m square Permalloy elements presented in Ref. 17. In Ref.…”

Section: Introductionmentioning

confidence: 83%

Section: Introductionmentioning

confidence: 99%