scholarly journals Micromagnetic Simulations for Spin Transfer Torque in Magnetic Multilayers

2012 ◽  
Vol 17 (2) ◽  
pp. 73-77 ◽  
Author(s):  
Chun-Yeol You
Keyword(s):  
Magnetic Multilayers ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Micromagnetic Simulations

Introduction of spin torques

2017 ◽  
Author(s):  
T. Kimura
Keyword(s):  
Angular Momentum ◽  
Giant Magnetoresistance ◽  
Spontaneous Magnetization ◽  
Magnetic Domain ◽  
Magnetic Multilayers ◽  
Transfer Effect ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Angular Momentum ◽  
Spin Torques

This chapter discusses the spin-transfer effect, which is described as the transfer of the spin angular momentum between the conduction electrons and the magnetization of the ferromagnet that occurs due to the conservation of the spin angular momentum. L. Berger, who introduced the concept in 1984, considered the exchange interaction between the conduction electron and the localized magnetic moment, and predicted that a magnetic domain wall can be moved by flowing the spin current. The spin-transfer effect was brought into the limelight by the progress in microfabrication techniques and the discovery of the giant magnetoresistance effect in magnetic multilayers. Berger, at the same time, separately studied the spin-transfer torque in a system similar to Slonczewski’s magnetic multilayered system and predicted spontaneous magnetization precession.

Modelling spin transfer torque and magnetoresistance in magnetic multilayers

2007 ◽  
Vol 19 (16) ◽  
pp. 165212 ◽  
Author(s):  
A Manchon ◽  
N Ryzhanova ◽  
N Strelkov ◽  
A Vedyayev ◽  
B Dieny
Keyword(s):  
Magnetic Multilayers ◽  
Spin Transfer Torque ◽  
Spin Transfer

Resonant excitation of coupled skyrmions by spin-transfer torque

2016 ◽  
Vol 30 (02) ◽  
pp. 1550254 ◽  
Author(s):  
Y. Y. Dai ◽  
H. Wang ◽  
T. Yang ◽  
Z. D. Zhang
Keyword(s):  
Microwave Field ◽  
Amplitude Ratio ◽  
Alternating Current ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Resonant Excitation ◽  
Dual Frequency ◽  
Magnetostatic Interaction ◽  
Micromagnetic Simulations

Resonant excitations of coupled skyrmions in Co/Ru/Co nanodisks activated by spin-transfer torque (STT) have been studied by micromagnetic simulations. It is found that STT is an effective method to manipulate skyrmion dynamics. Unlike the dynamics driven by a microwave field, two skyrmions with opposite chiralities move synchronously in the same direction when they are driven by STT, which makes it easier to observe the dynamics of coupled skyrmions in experiments. Resonant excitations of coupled skyrmions can be controlled by changing the frequency or amplitude ratio of a dual-frequency alternating current (AC). In addition, the magnetostatic interaction between the two skyrmions plays an important role in the dynamics of coupled skyrmions.

scholarly journals Theoretical Study of Field-Free Switching in PMA-MTJ Using Combined Injection of STT and SOT Currents

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1345
Author(s):  
Shaik Wasef ◽  
Hossein Fariborzi
Keyword(s):  
Critical Current ◽  
Theoretical Study ◽  
Tunnel Junctions ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Orbit ◽  
Micromagnetic Simulations ◽  
Spintronic Devices ◽  
Current Densities ◽  
The Relationship

Field-free switching in perpendicular magnetic tunnel junctions (P-MTJs) can be achieved by combined injection of spin-transfer torque (STT) and spin-orbit torque (SOT) currents. In this paper, we derived the relationship between the STT and SOT critical current densities under combined injection. We included the damping–like torque (DLT) and field-like torque (FLT) components of both the STT and SOT. The results were derived when the ratio of the FLT to the DLT component of the SOT was positive. We observed that the relationship between the critical SOT and STT current densities depended on the damping constant and the magnitude of the FLT component of the STT and the SOT current. We also noted that, unlike the FLT component of SOT, the magnitude and sign of the FLT component of STT did not have a significant effect on the STT and SOT current densities required for switching. The derived results agreed well with micromagnetic simulations. The results of this work can serve as a guideline to model and develop spintronic devices using a combined injection of STT and SOT currents.

Micromagnetic simulations of spin-wave normal modes and the spin-transfer-torque driven magnetization dynamics of a ferromagnetic cross

2014 ◽  
Vol 115 (17) ◽  
pp. 17D123 ◽  
Author(s):  
Tanmoy Pramanik ◽  
Urmimala Roy ◽  
Maxim Tsoi ◽  
Leonard F. Register ◽  
Sanjay K. Banerjee
Keyword(s):  
Spin Wave ◽  
Normal Modes ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Magnetization Dynamics ◽  
Micromagnetic Simulations ◽  
Wave Normal

Spin-Transfer-Torque Driven Vortex Dynamics in Electrodeposited Nanowire Spin-Valves

SPIN ◽  
2017 ◽  
Vol 07 (01) ◽  
pp. 1740007 ◽  
Author(s):  
Flavio Abreu Araujo ◽  
Luc Piraux
Keyword(s):  
Magnetic Field ◽  
Porous Alumina ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Microwave Emission ◽  
Spin Valves ◽  
Zero Magnetic Field ◽  
Micromagnetic Simulations ◽  
Magnetic Layers ◽  
In Series

A bottom-up approach for the fabrication of an assembly of electrodeposited nanowires has been combined to single nanowire electrical connection techniques to investigate the spin-transfer-torque and microwave emission of specially designed nanowires containing Co/Cu/Co pseudo spin-valves (SVs). Porous alumina templates are used for the growth by electrodeposition of metallic in-series connected SVs. Under specific magnetic field and injected current conditions, emission of microwave current is detected with frequency in the GHz range and linewidth as low as 1.8[Formula: see text]MHz. Microwave signals have been obtained even at zero magnetic field and high frequency versus magnetic field tunability was demonstrated. Our findings are in good agreement with micromagnetic simulations. In addition, it appears that in our particular geometry, the microwave emission is generated by the vortex gyrotropic motion which occurs in, at least, one of the two magnetic layers of our SV structures.

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