Simulation of high k-vector spin wave excitation with periodic ferromagnetic strips

Heimbach, Florian; Stückler, Tobias; Yu, Haiming; Zhao, Weisheng

doi:10.1016/j.jmmm.2017.09.062

Cited by 6 publications

(3 citation statements)

References 27 publications

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“…Periodically patterned magnetic materials with periodicities ranging from micrometers down to several tens of nanometers are referred to as magnonic crystals (MCs). [1][2][3][4][5][6][7][8][9] In the last decade, this group of metamaterials, such as bi-component systems, [10][11][12][13][14][15][16] free standing structures, [17][18][19][20][21][22] and continuous films with periodic structures on top, also known as surface-modulated magnonic crystals (SMMCs), [23][24][25][26][27][28][29][30] experienced a growing scientific interest. As spin waves (SWs) offer unique properties such as charge-less propagation and high group velocities, there are multiple applications conceivable since industry is in need for higher efficiencies as well as high performances in information technology including the transport and processing of data.…”

Section: Introductionmentioning

confidence: 99%

Spin-wave modes in transition from a thin film to a full magnonic crystal

et al. 2019

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Surface-modulated magnonic crystals are the natural link between continuous films with sinusoidal spin-wave eigenmodes and one-dimensional magnonic crystals composed of individual nanowires. Nevertheless, the transformation process of the spin-wave modes in this transition remains yet unclear. Here, spin-wave modes in their entire transition from a flat film to a 'full' (one-dimensional) magnonic crystal are studied by ferromagnetic resonance (FMR) and micromagnetic simulations. For this purpose, the surface of a pre-patterned thin permalloy film was sequentially ion milled resulting in hybrid structures, referred to as surface-modulated magnonic crystals, with increasing modulation depth. After each step, FMR measurements were carried out in backward-volume and Damon-Eshbach geometry. The evolution of each spin-wave resonance is studied together with the corresponding mode profile obtained by micromagnetic simulations. Simple rules describing the transition of the modes from the film to the modes of the full magnonic crystal are provided unraveling the complexity of spin-wave states in these hybrid systems.

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Section: Introductionmentioning

confidence: 99%

Spin-wave modes in transition from a thin film to a full magnonic crystal

et al. 2019

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“…However, short-wavelength magnon excitation, diminishing magnetization [23,24], plays an important role in magnetic relaxation, especially in thin film structures [25][26][27][28]. Moreover, all types of magnons, with wavelengths short and long, are the concern of magnon spintronics [29][30][31].…”

Section: Theoretical Modelmentioning

confidence: 99%

Terahertz spin-transfer torque oscillator based on a synthetic antiferromagnet

Zhong

Qiao

Shen

et al. 2020

Journal of Magnetism and Magnetic Materials

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Bloch-Bloembergen-Slonczewski equation is adopted to simulate magnetization dynamics in spin-valve based spin-transfer torque oscillator with synthetic antiferromagnet acting as a free magnetic layer. High frequency up to the terahertz scale is predicted in synthetic antiferromagnet spin-transfer torque oscillator with no external magnetic field if the following requirements are fulfilled: antiferromagnetic coupling between synthetic antiferromagnetic layers is sufficiently strong, and the thickness of top (bottom) layer of synthetic antiferromagnet is sufficiently thick (thin) to achieve a wide current density window for the high oscillation frequency. Additionally, the transverse relaxation time of the free magnetic layer should be sufficiently larger compared with the longitudinal relaxation time. Otherwise, stable oscillation cannot be sustained or scenarios similar to regular spin valve-based spin-transfer torque oscillator with relatively low frequency will occur. Our calculations pave a new way for exploring THz spintronics devices.

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“…Note that velocities v gt are derived assuming the empty lattice model. In the real sample, nanodisks of finite lateral dimensions are present that we expect to modify the band structure of the YIG which is underneath 30,31 . We attribute the discrepancies between the absolute values of v g and v gt to the influence of the nanomagnets.…”

mentioning

confidence: 99%

Multi-directional emission and detection of spin waves propagating in yttrium iron garnet with wavelengths down to about 100 nm

Maendl

Grundler

2018

Applied Physics Letters

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We performed broadband spin-wave spectroscopy on 200 nm thick yttrium iron garnet containing arrays of partially embedded magnetic nanodisks. Using integrated coplanar waveguides (CPWs), we studied the excitation and transmission of spin waves depending on the presence of nanomagnet arrays of different lateral extensions. By means of the grating coupler effect, we excited spin waves propagating in multiple lateral directions with wavelengths down to 111 nm. They exhibited group velocities of up to 1 km/s. Detection of such short-wavelength spin waves was possible only in symmetrically designed emitter/detector configurations, not with a bare CPW. We report spin waves propagating between grating couplers under oblique angles exhibiting a wave vector component parallel to the CPW. The effective propagation distance amounted to about 80 μm. Such transmission signals were not addressed before and substantiate the versatility of the grating coupler effect for implementing nanomagnonic circuits.

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Simulation of high k-vector spin wave excitation with periodic ferromagnetic strips

Cited by 6 publications

References 27 publications

Spin-wave modes in transition from a thin film to a full magnonic crystal

Spin-wave modes in transition from a thin film to a full magnonic crystal

Terahertz spin-transfer torque oscillator based on a synthetic antiferromagnet

Multi-directional emission and detection of spin waves propagating in yttrium iron garnet with wavelengths down to about 100 nm

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