scholarly journals Demonstration of k-vector selective microscopy for nanoscale mapping of higher order spin wave modes

Nanoscale ◽  
2020 ◽  
Vol 12 (33) ◽  
pp. 17238-17244 ◽  
Author(s):  
Nick Träger ◽  
Paweł Gruszecki ◽  
Filip Lisiecki ◽  
Felix Groß ◽  
Johannes Förster ◽  
...  
Keyword(s):  
Spin Wave ◽  
Real Space ◽  
Higher Order ◽  
Time Resolved ◽  
Excited Mode ◽  
Wave Modes

Time resolved STXM provides deep insights into efficient excitation of symmetric and antisysmmetric higher order spin wave modes in magnonic waveguides. k-selective imaging reveals real space information of simultaneously excited mode patterns.

scholarly journals Electrical characterisation of higher order spin wave modes in vortex-based magnetic tunnel junctions

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Alex. S. Jenkins ◽  
Lara San Emeterio Alvarez ◽  
Samh Memshawy ◽  
Paolo Bortolotti ◽  
Vincent Cros ◽  
...  
Keyword(s):  
Spin Wave ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Higher Order ◽  
Spin Torque ◽  
Micromagnetic Simulations ◽  
Higher Order Modes ◽  
Spin Diode ◽  
Super High Frequency ◽  
Wave Modes

AbstractNiFe-based vortex spin-torque nano-oscillators (STNO) have been shown to be rich dynamic systems which can operate as efficient frequency generators and detectors, but with a limitation in frequency determined by the gyrotropic frequency, typically sub-GHz. In this report, we present a detailed analysis of the nature of the higher order spin wave modes which exist in the Super High Frequency range (3–30 GHz). This is achieved via micromagnetic simulations and electrical characterisation in magnetic tunnel junctions, both directly via the spin-diode effect and indirectly via the measurement of the coupling with the gyrotropic critical current. The excitation mechanism and spatial profile of the modes are shown to have a complex dependence on the vortex core position. Additionally, the inter-mode coupling between the fundamental gyrotropic mode and the higher order modes is shown to reduce or enhance the effective damping depending upon the sense of propagation of the confined spin wave.

scholarly journals Ultrafast magnetization dynamics in a nanoscale three-dimensional cobalt tetrapod structure

Nanoscale ◽  
2018 ◽  
Vol 10 (21) ◽  
pp. 9981-9986 ◽  
Author(s):  
Sourav Sahoo ◽  
Sucheta Mondal ◽  
Gwilym Williams ◽  
Andrew May ◽  
Sam Ladak ◽  
...  
Keyword(s):  
Spin Wave ◽  
Numerical Study ◽  
Spin Dynamics ◽  
Three Dimensional ◽  
Magnetization Dynamics ◽  
Time Resolved ◽  
Complex Spin ◽  
Ultrafast Magnetization ◽  
Wave Modes

Time resolved measurement and numerical study of ultrafast spin dynamics in a 3D Co tetrapod structure revealed complex spin-wave modes.

scholarly journals Identification and time-resolved study of ferrimagnetic spin-wave modes in a microwave cavity in the strong-coupling regime

2020 ◽  
Vol 101 (1) ◽  
Author(s):  
Angelo Leo ◽  
Anna Grazia Monteduro ◽  
Silvia Rizzato ◽  
Luigi Martina ◽  
Giuseppe Maruccio
Keyword(s):  
Strong Coupling ◽  
Spin Wave ◽  
Microwave Cavity ◽  
Strong Coupling Regime ◽  
Time Resolved ◽  
Wave Modes

scholarly journals Higher order Hamiltonian Monte Carlo sampling for cosmological large-scale structure analysis

2021 ◽  
Vol 502 (3) ◽  
pp. 3976-3992
Author(s):  
Mónica Hernández-Sánchez ◽  
Francisco-Shu Kitaura ◽  
Metin Ata ◽  
Claudio Dalla Vecchia
Keyword(s):  
Fourth Order ◽  
Large Scale ◽  
Equations Of Motion ◽  
Large Scale Structure ◽  
Real Space ◽  
Higher Order ◽  
Second Order ◽  
Scale Structure ◽  
Integration Schemes ◽  
Reconstruction Methods

ABSTRACT We investigate higher order symplectic integration strategies within Bayesian cosmic density field reconstruction methods. In particular, we study the fourth-order discretization of Hamiltonian equations of motion (EoM). This is achieved by recursively applying the basic second-order leap-frog scheme (considering the single evaluation of the EoM) in a combination of even numbers of forward time integration steps with a single intermediate backward step. This largely reduces the number of evaluations and random gradient computations, as required in the usual second-order case for high-dimensional cases. We restrict this study to the lognormal-Poisson model, applied to a full volume halo catalogue in real space on a cubical mesh of 1250 h−1 Mpc side and 2563 cells. Hence, we neglect selection effects, redshift space distortions, and displacements. We note that those observational and cosmic evolution effects can be accounted for in subsequent Gibbs-sampling steps within the COSMIC BIRTH algorithm. We find that going from the usual second to fourth order in the leap-frog scheme shortens the burn-in phase by a factor of at least ∼30. This implies that 75–90 independent samples are obtained while the fastest second-order method converges. After convergence, the correlation lengths indicate an improvement factor of about 3.0 fewer gradient computations for meshes of 2563 cells. In the considered cosmological scenario, the traditional leap-frog scheme turns out to outperform higher order integration schemes only when considering lower dimensional problems, e.g. meshes with 643 cells. This gain in computational efficiency can help to go towards a full Bayesian analysis of the cosmological large-scale structure for upcoming galaxy surveys.

scholarly journals Phase resolved observation of spin wave modes in antidot lattices

2021 ◽  
Vol 118 (23) ◽  
pp. 232403
Author(s):  
Felix Groß ◽  
Mateusz Zelent ◽  
Ajay Gangwar ◽  
Sławomir Mamica ◽  
Paweł Gruszecki ◽  
...  
Keyword(s):  
Spin Wave ◽  
Wave Modes

Intensity distribution, evolution, and dispersion of discrete spin wave modes in nanoscale spin-torque oscillator

2021 ◽  
Vol 129 (24) ◽  
pp. 243903
Author(s):  
Shizhu Qiao ◽  
Lihui Bai ◽  
Haibin Xue ◽  
Lipeng Hou ◽  
Lijuan Zhang ◽  
...  
Keyword(s):  
Spin Wave ◽  
Intensity Distribution ◽  
Spin Torque ◽  
Wave Modes

Contribution of Lamb wave modes in the formation of higher order modes cluster (HOMC) guided waves

2021 ◽  
pp. 095440622110424
Author(s):  
Z Abbasi ◽  
F Honarvar
Keyword(s):  
Finite Element ◽  
Wave Packet ◽  
Lamb Wave ◽  
Guided Waves ◽  
Element Model ◽  
Higher Order ◽  
Guided Wave ◽  
Cross Sectional ◽  
Higher Order Modes ◽  
Wave Modes

In recent years, Higher Order Modes Cluster (HOMC) guided waves have been considered for ultrasonic testing of plates and pipes. HOMC guided waves consist of higher order Lamb wave modes that travel together as a single nondispersive wave packet. The objective of this paper is to investigate the effect of frequency-thickness value on the contribution of Lamb wave modes in an HOMC guided wave. This is an important issue that has not been thoroughly investigated before. The contribution of each Lamb wave mode in an HOMC guided wave is studied by using a two-dimensional finite element model. The level of contribution of various Lamb wave modes to the wave cluster is verified by using a 2D FFT analysis. The results show that by increasing the frequency-thickness value, the order of contributing modes in the HOMC wave packet increases. The number of modes that comprise a cluster also increases up to a specific frequency-thickness value and then it starts to decrease. Plotting of the cross-sectional displacement patterns along the HOMC guided wave paths confirms the shifting of dominant modes from lower to higher order modes with increase of frequency-thickness value. Experimental measurements conducted on a mild steel plate are used to verify the finite element simulations. The experimental results are found to be in good agreement with simulations and confirm the changes observed in the level of contribution of Lamb wave modes in a wave cluster by changing the frequency-thickness value.

scholarly journals Size-dependent magnetization switching characteristics and spin wave modes of FePt nanostructures

2013 ◽  
Vol 113 (20) ◽  
pp. 203910 ◽  
Author(s):  
R. Brandt ◽  
R. Rückriem ◽  
D. A. Gilbert ◽  
F. Ganss ◽  
T. Senn ◽  
...  
Keyword(s):  
Spin Wave ◽  
Magnetization Switching ◽  
Size Dependent ◽  
Switching Characteristics ◽  
Wave Modes

Thermally excited spin wave modes in synthetic antiferromagnetic stripes

2007 ◽  
Vol 310 (2) ◽  
pp. 1949-1951 ◽  
Author(s):  
Yasuo Ando ◽  
Young Min Lee ◽  
Tatsuya Aoki ◽  
Terunobu Miyazaki ◽  
Helmut Schultheiß ◽  
...  
Keyword(s):  
Spin Wave ◽  
Wave Modes
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