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 ◽  
...  

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.

2021 ◽  
Vol 104 (6) ◽  
Author(s):  
Tobias Dannegger ◽  
Marco Berritta ◽  
Karel Carva ◽  
Severin Selzer ◽  
Ulrike Ritzmann ◽  
...  

2005 ◽  
Author(s):  
Ileana Rau ◽  
Pierre-Alain Chollet ◽  
Francois Kajzar ◽  
Roberto Zamboni

2018 ◽  
Vol 32 (28) ◽  
pp. 1830003 ◽  
Author(s):  
G. P. Zhang ◽  
M. Murakami ◽  
M. S. Si ◽  
Y. H. Bai ◽  
Thomas F. George

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.


2019 ◽  
Vol 100 (6) ◽  
Author(s):  
Yong Xu ◽  
Michel Hehn ◽  
Weisheng Zhao ◽  
Xiaoyang Lin ◽  
Grégory Malinowski ◽  
...  

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
D. O. Ignatyeva ◽  
C. S. Davies ◽  
D. A. Sylgacheva ◽  
A. Tsukamoto ◽  
H. Yoshikawa ◽  
...  

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.


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