scholarly journals All-Optical Switching of Magnetic Tunnel Junctions with Single Subpicosecond Laser Pulses

2017 ◽  
Vol 7 (2) ◽  
Author(s):  
Jun-Yang Chen ◽  
Li He ◽  
Jian-Ping Wang ◽  
Mo Li
Keyword(s):  
Optical Switching ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Laser Pulses ◽  
All Optical ◽  
All Optical Switching

scholarly journals Understanding all-optical spin switching: Comparison between experiment and theory

2018 ◽  
Vol 32 (28) ◽  
pp. 1830003 ◽  
Author(s):  
G. P. Zhang ◽  
M. Murakami ◽  
M. S. Si ◽  
Y. H. Bai ◽  
Thomas F. George
Keyword(s):  
Optical Switching ◽  
Magnetic Domain ◽  
Laser Pulses ◽  
Underlying Mechanism ◽  
Modern Technology ◽  
Single Shot ◽  
Ultrafast Laser Pulses ◽  
All Optical ◽  
Multiple Pulses ◽  
All Optical Switching

Information technology depends on how one can control and manipulate signals accurately and quickly. Transistors are at the core of modern technology and are based on electron charges. But as the device dimension shrinks, heating becomes a major problem. The spintronics explores the spin degree of electrons and thus bypasses the heat, at least in principle. For this reason, spin-based technology offers a possible solution. In this review, we survey some of the latest developments in all-optical switching (AOS), where ultrafast laser pulses are able to reverse spins from one direction to the other deterministically. But AOS only occurs in a special group of magnetic samples and within a narrow window of laser parameters. Some samples need multiple pulses to switch spins, while others need a single-shot pulse. To this end, there are several models available, but the underlying mechanism is still under debate. This review is different from other prior reviews in two aspects. First, we sacrifice the completeness of reviewing existing studies, while focusing on a limited set of experimental results that are highly reproducible in different labs and provide actual switched magnetic domain images. Second, we extract the common features from existing experiments that are critical to AOS, without favoring a particular switching mechanism. We emphasize that given the limited experimental data, it is really premature to identify a unified mechanism. We compare these features with our own model prediction, without resorting to a phenomenological scheme. We hope that this review serves the broad readership well.

scholarly journals Plasmonic layer-selective all-optical switching of magnetization with nanometer resolution

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
D. O. Ignatyeva ◽  
C. S. Davies ◽  
D. A. Sylgacheva ◽  
A. Tsukamoto ◽  
H. Yoshikawa ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Magnetic Recording ◽  
Optical Switching ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
All Optical ◽  
Polarization Axis ◽  
Linearly Polarized ◽  
All Optical Switching ◽  
Better Than

Abstract All-optical magnetization reversal with femtosecond laser pulses facilitates the fastest and least dissipative magnetic recording, but writing magnetic bits with spatial resolution better than the wavelength of light has so far been seen as a major challenge. Here, we demonstrate that a single femtosecond laser pulse of wavelength 800 nm can be used to toggle the magnetization exclusively within one of two 10-nm thick magnetic nanolayers, separated by just 80 nm, without affecting the other one. The choice of the addressed layer is enabled by the excitation of a plasmon-polariton at a targeted interface of the nanostructure, and realized merely by rotating the polarization-axis of the linearly-polarized ultrashort optical pulse by 90°. Our results unveil a robust tool that can be deployed to reliably switch magnetization in targeted nanolayers of heterostructures, and paves the way to increasing the storage density of opto-magnetic recording by a factor of at least 2.

scholarly journals All-optical spin switching probability in [Tb/Co] multilayers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. Avilés-Félix ◽  
L. Farcis ◽  
Z. Jin ◽  
L. Álvaro-Gómez ◽  
G. Li ◽  
...  
Keyword(s):  
Optical Switching ◽  
Laser Pulses ◽  
Multilayered Structures ◽  
Magnetization Switching ◽  
Thermally Induced ◽  
Spintronic Devices ◽  
Single Laser ◽  
All Optical ◽  
Reversal Mechanism ◽  
All Optical Switching

AbstractSince the first experimental observation of all-optical switching phenomena, intensive research has been focused on finding suitable magnetic systems that can be integrated as storage elements within spintronic devices and whose magnetization can be controlled through ultra-short single laser pulses. We report here atomistic spin simulations of all-optical switching in multilayered structures alternating n monolayers of Tb and m monolayers of Co. By using a two temperature model, we numerically calculate the thermal variation of the magnetization of each sublattice as well as the magnetization dynamics of [$$\text {Tb}_n$$ Tb n /$$\text {Co}_m$$ Co m ] multilayers upon incidence of a single laser pulse. In particular, the condition to observe thermally-induced magnetization switching is investigated upon varying systematically both the composition of the sample (n,m) and the laser fluence. The samples with one monolayer of Tb as [$$\text {Tb}_1$$ Tb 1 /$$\text {Co}_2$$ Co 2 ] and [$$\text {Tb}_1$$ Tb 1 /$$\text {Co}_3$$ Co 3 ] are showing thermally induced magnetization switching above a fluence threshold. The reversal mechanism is mediated by the residual magnetization of the Tb lattice while the Co is fully demagnetized in agreement with the models developed for ferrimagnetic alloys. The switching is however not fully deterministic but the error rate can be tuned by the damping parameter. Increasing the number of monolayers the switching becomes completely stochastic. The intermixing at the Tb/Co interfaces appears to be a promising way to reduce the stochasticity. These results predict for the first time the possibility of TIMS in [Tb/Co] multilayers and suggest the occurrence of sub-picosecond magnetization reversal using single laser pulses.

scholarly journals Micromagnetic Modeling of All Optical Switching of Ferromagnetic Thin Films: The Role of Inverse Faraday Effect and Magnetic Circular Dichroism

2020 ◽  
Vol 10 (4) ◽  
pp. 1307 ◽  
Author(s):  
Victor Raposo ◽  
Rodrigo Guedas ◽  
Felipe García-Sánchez ◽  
M. Auxiliadora Hernández ◽  
Marcelino Zazo ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Switching ◽  
Faraday Effect ◽  
Magnetic Circular Dichroism ◽  
Laser Pulses ◽  
Inverse Faraday Effect ◽  
Ferromagnetic Thin Films ◽  
All Optical ◽  
Circular Dichroïsm ◽  
All Optical Switching

There is a lot of experimental evidence of All Optical Switching (AOS) by applying ultrashort laser pulses on ferromagnetic thin films with perpendicular magnetic anisotropy. However, the physical origin behind these processes remains under debate. In addition to the heating caused by the laser pulses, the Inverse Faraday Effect (IFE) and Magnetic Circular Dichroism (MCD) have been proposed as the most probable phenomena responsible for the observations of helicity-dependent AOS. Here, we review the influence of both phenomena by means of realistic micromagnetic simulations based on the Landau–Lifshitz–Bloch equation coupled to the heat transport caused by the laser heating. The analysis allows us to reveal the similarities and differences between both effects. While both mechanisms may lead to the local inversion of the initial magnetic state of a ferromagnetic sample submitted to a train of circularly polarized laser pulses, the Inverse Faraday Effect proves to be more efficient for nucleation and domain wall movement and it reproduces more accurately the different magnetic configurations that the experiments report for different values of the fluence of the laser beam.

scholarly journals All-Optical Switching Based on the Plasma Channel Induced by Laser Pulses

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Chao Tan ◽  
Binliang Hu ◽  
Shiping Zhan ◽  
Yonghua Hu ◽  
Bin Zhong
Keyword(s):  
Optical Switching ◽  
Plasma Channel ◽  
Laser Pulses ◽  
Dark Spot ◽  
Incident Intensity ◽  
Signal Light ◽  
All Optical ◽  
Signal Laser ◽  
All Optical Switching ◽  
Control Laser

We display a theoretical and experimental study of all-optical switching for signal lasers based on the plasma channel induced by the control laser. Using the plasma channel generated in the carbon disulfide (CS2) solution, the signal light can be modulated as some spatial distributions including unchanging, ring-shaped beam, and other intensity profiles. The modulation on the signal light can be conveniently adjusted by changing the control light’s incident intensity distribution. We can infer the dark spot shape in the modulated signal laser through the intensity profile of control laser beam. These results provide the great potential of plasma channel induced by lasers as an all-optical switching for various optoelectronic applications.

scholarly journals Deterministic all-optical switching of synthetic ferrimagnets using single femtosecond laser pulses

2017 ◽  
Vol 96 (22) ◽  
Author(s):  
M. L. M. Lalieu ◽  
M. J. G. Peeters ◽  
S. R. R. Haenen ◽  
R. Lavrijsen ◽  
B. Koopmans
Keyword(s):  
Femtosecond Laser ◽  
Optical Switching ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
All Optical ◽  
All Optical Switching
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