scholarly journals Micromagnetic simulations of spin-torque driven magnetization dynamics with spatially resolved spin transport and magnetization texture

2017 ◽  
Vol 96 (9) ◽  
Author(s):  
Simone Borlenghi ◽  
M. R. Mahani ◽  
Hans Fangohr ◽  
M. Franchin ◽  
Anna Delin ◽  
...  
Keyword(s):  
Spin Transport ◽  
Spin Torque ◽  
Magnetization Dynamics ◽  
Micromagnetic Simulations ◽  
Spatially Resolved

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.

Interplay Between Magnetization Dynamics and Spin Transport

2010 ◽  
Vol 46 (6) ◽  
pp. 2297-2302 ◽  
Author(s):  
Steven S.-L. Zhang ◽  
Shufeng Zhang
Keyword(s):  
Spin Transport ◽  
Magnetization Dynamics

SNR Improvement of Envelope Demodulation Using Two Temporal Magnetization Dynamics From Dual-Spin-Torque Oscillator

2018 ◽  
Vol 54 (11) ◽  
pp. 1-4 ◽  
Author(s):  
Y. Nakamura ◽  
M. Nishikawa ◽  
H. Osawa ◽  
Y. Okamoto ◽  
T. Kanao ◽  
...  
Keyword(s):  
Spin Torque ◽  
Magnetization Dynamics ◽  
Snr Improvement

scholarly journals Magnetization Dynamics in a Perpendicular Anisotropy Free Layer under a Spin Torque Effect with Crossed Polarization

2020 ◽  
Vol 25 (1) ◽  
pp. 54
Author(s):  
Nafeesa Rahman ◽  
Rachid Sbiaa
Keyword(s):  
Tunnel Junction ◽  
Magnetic Tunnel Junction ◽  
Film Plane ◽  
Spin Torque ◽  
Spin Angular Momentum ◽  
Perpendicular Anisotropy ◽  
Free Layer ◽  
Magnetization Dynamics ◽  
Magnetization Direction ◽  
Spin Polarized

The transfer of spin angular momentum from a spin polarized current provides an efficient way of reversing the magnetization direction of the free layer of the magnetic tunnel junction (MTJ), and while faster reversal will reduce the switching energy, this in turn will lead to low power consumption. In this work, we propose a design where a spin torque oscillator (STO) is integrated with a conventional magnetic tunnel junction (MTJ) which will assist in the ultrafast reversal of the magnetization of the free layer of the MTJ. The structure formed (MTJ stacked with STO), will have the free layer of the MTJ sandwiched between two spin polarizer layers, one with a fixed magnetization direction perpendicular to film plane (main static polarizer) and the other with an oscillatory magnetization (dynamic polarizer). The static polarizer is the fixed layer of the MTJ itself and the dynamic polarizer is the free layer of the STO.

Circuit Simulation of Magnetization Dynamics and Spin Transport

2014 ◽  
Vol 61 (5) ◽  
pp. 1553-1560 ◽  
Author(s):  
Phillip Bonhomme ◽  
Sasikanth Manipatruni ◽  
Rouhollah M. Iraei ◽  
Shaloo Rakheja ◽  
Sou-Chi Chang ◽  
...  
Keyword(s):  
Spin Transport ◽  
Circuit Simulation ◽  
Magnetization Dynamics

scholarly journals Magnetization dynamics of weakly interacting sub-100 nm square artificial spin ices

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jose M. Porro ◽  
Sophie A. Morley ◽  
Diego Alba Venero ◽  
Rair Macêdo ◽  
Mark C. Rosamond ◽  
...  
Keyword(s):  
Interaction Energy ◽  
Effective Interaction ◽  
Interaction Strength ◽  
Blocking Temperature ◽  
Magnetization Dynamics ◽  
Magnetization Relaxation ◽  
Strongly Coupled ◽  
Micromagnetic Simulations ◽  
Artificial Spin Ice ◽  
Different Temperatures

AbstractArtificial Spin Ice (ASI), consisting of a two dimensional array of nanoscale magnetic elements, provides a fascinating opportunity to observe the physics of out-of-equilibrium systems. Initial studies concentrated on the static, frozen state, whilst more recent studies have accessed the out-of-equilibrium dynamic, fluctuating state. This opens up exciting possibilities such as the observation of systems exploring their energy landscape through monopole quasiparticle creation, potentially leading to ASI magnetricity, and to directly observe unconventional phase transitions. In this work we have measured and analysed the magnetic relaxation of thermally active ASI systems by means of SQUID magnetometry. We have investigated the effect of the interaction strength on the magnetization dynamics at different temperatures in the range where the nanomagnets are thermally active. We have observed that they follow an Arrhenius-type Néel-Brown behaviour. An unexpected negative correlation of the average blocking temperature with the interaction strength is also observed, which is supported by Monte Carlo simulations. The magnetization relaxation measurements show faster relaxation for more strongly coupled nanoelements with similar dimensions. The analysis of the stretching exponents obtained from the measurements suggest 1-D chain-like magnetization dynamics. This indicates that the nature of the interactions between nanoelements lowers the dimensionality of the ASI from 2-D to 1-D. Finally, we present a way to quantify the effective interaction energy of a square ASI system, and compare it to the interaction energy computed with micromagnetic simulations.

scholarly journals A cryogenic spin-torque memory element with precessional magnetization dynamics

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
G. E. Rowlands ◽  
C. A. Ryan ◽  
L. Ye ◽  
L. Rehm ◽  
D. Pinna ◽  
...  
Keyword(s):  
Spin Torque ◽  
Magnetization Dynamics ◽  
Memory Element

Stability Analysis of Spin-Torque Nano-oscillator in the Rotating Frame

SPIN ◽  
2019 ◽  
Vol 09 (03) ◽  
pp. 1950008
Author(s):  
HaoHsuan Chen ◽  
Lang Zeng ◽  
ChingMing Lee ◽  
Weisheng Zhao
Keyword(s):  
High Performance ◽  
Electrical Current ◽  
Nonstationary Process ◽  
Laboratory Frame ◽  
Spin Torque ◽  
Rotating Frame ◽  
Magnetization Dynamics ◽  
Applied Current ◽  
Frequency Tunability ◽  
Out Of Plane

Spin-torque nano-oscillators (STNOs) have become one of the emerging and novel microwave devices with the high performance and tunability of GHz range frequency. The nanopillar structure with an out-of-plane (OP) spin polarizer and an in-plane (IP) magnetized free layer (FL) has been considered as a good candidate for the STNOs. Using the local rotational coordinate transformation, a nonstationary process describing magnetization dynamics in the laboratory frame is therefore transformed into a stationary one in the rotating frame. In this way, the state phase diagram of this type of STNOs is well established as a function of an applied current and external field, which is also evidenced by the macrospin simulations. Also, we show that the frequency tunability of the STNOs through electrical current can be well elevated by applying a static magnetic field anti-parallel to the spin-polarizer vector.

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