Heat-induced magnetization dynamics due to ultrafast exchange scattering with itinerant electrons

2016 ◽  
Author(s):  
Alexander Baral ◽  
Svenja Vollmar ◽  
Hans Christian Schneider
Keyword(s):  
Magnetization Dynamics ◽  
Itinerant Electrons ◽  
Exchange Scattering

scholarly journals Ultrafast optical manipulation of magnetic order in ferromagnetic materials

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Chuangtang Wang ◽  
Yongmin Liu
Keyword(s):  
Data Storage ◽  
Optical Switching ◽  
Ultrafast Lasers ◽  
Transport Model ◽  
Magnetic Interaction ◽  
Ferromagnetic Materials ◽  
Magnetic Storage ◽  
Magnetization Dynamics ◽  
Quarter Century ◽  
Ultrafast Optical

Abstract The interaction between ultrafast lasers and magnetic materials is an appealing topic. It not only involves interesting fundamental questions that remain inconclusive and hence need further investigation, but also has the potential to revolutionize data storage technologies because such an opto-magnetic interaction provides an ultrafast and energy-efficient means to control magnetization. Fruitful progress has been made in this area over the past quarter century. In this paper, we review the state-of-the-art experimental and theoretical studies on magnetization dynamics and switching in ferromagnetic materials that are induced by ultrafast lasers. We start by describing the physical mechanisms of ultrafast demagnetization based on different experimental observations and theoretical methods. Both the spin-flip scattering theory and the superdiffusive spin transport model will be discussed in detail. Then, we will discuss laser-induced torques and resultant magnetization dynamics in ferromagnetic materials. Recent developments of all-optical switching (AOS) of ferromagnetic materials towards ultrafast magnetic storage and memory will also be reviewed, followed by the perspectives on the challenges and future directions in this emerging area.

scholarly journals Effect of strain-induced anisotropy on magnetization dynamics in Y3Fe5O12 films recrystallized on a lattice-mismatched substrate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam Krysztofik ◽  
Sevgi Özoğlu ◽  
Robert D. McMichael ◽  
Emerson Coy
Keyword(s):  
Dispersion Model ◽  
Perpendicular Magnetic Anisotropy ◽  
Negative Slope ◽  
Recrystallization Process ◽  
Induced Anisotropy ◽  
Magnetization Dynamics ◽  
Unexpected Formation ◽  
Lattice Matched ◽  
Ferromagnetic Resonance Linewidth ◽  
Lattice Mismatched Substrate

AbstractWe report on the correlation of structural and magnetic properties of Y3Fe5O12 (YIG) films deposited on Y3Al5O12 substrates using pulsed laser deposition. The recrystallization process leads to an unexpected formation of interfacial tensile strain and consequently strain-induced anisotropy contributing to the perpendicular magnetic anisotropy. The ferromagnetic resonance linewidth of YIG is significantly increased in comparison to a film on a lattice-matched Gd3Ga5O12 substrate. Notably, the linewidth dependency on frequency has a negative slope. The linewidth behavior is explained with the proposed anisotropy dispersion model.

scholarly journals Spin injection characteristics of Py/graphene/Pt by gigahertz and terahertz magnetization dynamics driven by femtosecond laser pulse

AIP Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 015321
Author(s):  
H. Idzuchi ◽  
S. Iihama ◽  
M. Shimura ◽  
A. Kumatani ◽  
S. Mizukami ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Spin Injection ◽  
Magnetization Dynamics

scholarly journals Route towards efficient magnetization reversal driven by voltage control of magnetic anisotropy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Roxana-Alina One ◽  
Hélène Béa ◽  
Sever Mican ◽  
Marius Joldos ◽  
Pedro Brandão Veiga ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Random Access ◽  
Low Power Consumption ◽  
Surface Anisotropy ◽  
Magnetization Dynamics ◽  
Storage Density ◽  
Switching Regime ◽  
Major Interest ◽  
Out Of Plane

AbstractThe voltage controlled magnetic anisotropy (VCMA) becomes a subject of major interest for spintronics due to its promising potential outcome: fast magnetization manipulation in magnetoresistive random access memories with enhanced storage density and very low power consumption. Using a macrospin approach, we carried out a thorough analysis of the role of the VCMA on the magnetization dynamics of nanostructures with out-of-plane magnetic anisotropy. Diagrams of the magnetization switching have been computed depending on the material and experiment parameters (surface anisotropy, Gilbert damping, duration/amplitude of electric and magnetic field pulses) thus allowing predictive sets of parameters for optimum switching experiments. Two characteristic times of the trajectory of the magnetization were analyzed analytically and numerically setting a lower limit for the duration of the pulses. An interesting switching regime has been identified where the precessional reversal of magnetization does not depend on the voltage pulse duration. This represents a promising path for the magnetization control by VCMA with enhanced versatility.

scholarly journals Magnetic Normal Mode Calculations in Big Systems: A Highly Scalable Dynamical Matrix Approach Applied to a Fibonacci-Distorted Artificial Spin Ice

2021 ◽  
Vol 7 (3) ◽  
pp. 34
Author(s):  
Loris Giovannini ◽  
Barry W. Farmer ◽  
Justin S. Woods ◽  
Ali Frotanpour ◽  
Lance E. De Long ◽  
...  
Keyword(s):  
Normal Modes ◽  
Low Frequency ◽  
Fibonacci Sequence ◽  
Exchange Interactions ◽  
Geometric Distortion ◽  
Dynamical Matrix ◽  
Spin Ice ◽  
Magnetization Dynamics ◽  
Distortion Parameter ◽  
Artificial Spin Ice

We present a new formulation of the dynamical matrix method for computing the magnetic normal modes of a large system, resulting in a highly scalable approach. The motion equation, which takes into account external field, dipolar and ferromagnetic exchange interactions, is rewritten in the form of a generalized eigenvalue problem without any additional approximation. For its numerical implementation several solvers have been explored, along with preconditioning methods. This reformulation was conceived to extend the study of magnetization dynamics to a broader class of finer-mesh systems, such as three-dimensional, irregular or defective structures, which in recent times raised the interest among researchers. To test its effectiveness, we applied the method to investigate the magnetization dynamics of a hexagonal artificial spin-ice as a function of a geometric distortion parameter following the Fibonacci sequence. We found several important features characterizing the low frequency spin modes as the geometric distortion is gradually increased.

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