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Related papers: Ultrafast demagnetization dynamics in Ni: role of …

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The spin dynamics in Ni is studied by an exact diagonalization method on the ultrafast time scale. It is shown that the femtosecond relaxation of the magneto-optical response results from exchange interaction and spin-orbit coupling. Each…

Materials Science · Physics 2009-10-30 W. Hubner , G. P. Zhang

Time-dependent density functional theory is implemented in an all electron solid-state code for the case of fully non-collinear spins. We use this to study laser induced demagnetization in Fe, Co and Ni. It is shown that this…

Materials Science · Physics 2014-06-26 K. Krieger , J. K. Dewhurst , P. Elliott , S. Sharma , E. K. U. Gross

A joint theoretical and experimental investigation is performed to understand the underlying physics of laser-induced demagnetization in Ni and Co films. Experimentally dynamics of spins is studied by determining the time-dependent…

We propose a semi-classical model for femtosecond-laser induced demagnetization due to spin-polarized excited electron diffusion in the super-diffusive regime. Our approach treats the finite elapsed time and transport in space between…

Materials Science · Physics 2011-06-14 Marco Battiato , Karel Carva , Peter M. Oppeneer

We report on {\it ab-initio} simulations of the quantum dynamics of electronic charge and spin when subjected to intense laser pulses. By performing separate calculations for a Ni thin film and bulk Ni, we conclude that surface effects have…

Materials Science · Physics 2017-05-24 K. Krieger , P. Elliott , T. Müller , N. Singh , J. K. Dewhurst , E. K. U. Gross , S. Sharma

We investigate ultrafast demagnetization due to electron-phonon interaction in a model band-ferromagnet. We show that the microscopic mechanism behind the spin dynamics due to electron-phonon interaction is the interplay of scattering and…

Materials Science · Physics 2017-10-25 Kai Leckron , Svenja Vollmar , Hans Christian Schneider

Induced by an ultra-short laser pulse, the electronic structure of a material undergoes strong modifications leading to a fast demagnetization in magnetic materials. Induced spin-flip transitions are one of the reasons for demagnetization,…

Materials Science · Physics 2024-04-29 Sergiy Mankovsky , Svitlana Polesya , Hubert Ebert

Element specific ultrafast demagnetization was studied in Fe$_{1-x}$Ni$_{x}$ alloys, covering the concentration range between $0.1<x<0.9$. For all compositions, we observe a delay in the onset of Ni demagnetization relative to the Fe…

Here we carry out a first-principles time-dependent calculation to investigate how fast electrons actually move under laser excitation and how large the electron transport affects demagnetization on the shortest time scale. To take into…

Materials Science · Physics 2018-11-14 G. P. Zhang , Y. H. Bai , T. Jenkins , T. F. George

Since the beginning of femtomagnetism, it has been hotly debated how an ultrafast laser pulse can demagnetize a sample and switch its spins within a few hundred femtoseconds, but no consensus has been reached. In this paper, we propose that…

Materials Science · Physics 2015-06-22 G. P. Zhang , Mingqiang Gu , X. S. Wu

Ultrafast magnetization dynamics induced by femtosecond laser pulses have been measured in ferrimagnetic Co0.8Gd0.2, Co.74Tb.26 and Co.86Tb.14 alloys. Using element sensitivity of X-ray magnetic circular dichroism at the Co L3, Tb M5 and Gd…

Materials Science · Physics 2015-06-12 V. Lopez-Flores , N. Bergeard , V. Halte , C Stamm , N. Pontius , M. Hehn , E. Otero , E. Beaurepaire , C. Boeglin

Irradiating a ferromagnetic material with an ultrashort laser pulse leads to demagnetization on a femtosecond timescale. We implement Elliott-Yafet type spin-flip scattering, mediated by electron-electron and electron-phonon collisions,…

Materials Science · Physics 2011-08-29 Benedikt Y. Mueller , T. Roth , M. Cinchetti , M. Aeschlimann , B. Rethfeld

Interest in femtosecond demagnetization experiments was sparked by Bigot's discovery in 1995. These experiments unveil the elementary mechanisms coupling the electrons' temperature to their spin order. Even though first quantitative models…

The ultrafast dynamics of magnetic order in a ferromagnet are governed by the interplay between electronic, magnetic and lattice degrees of freedom. In order to obtain a microscopic understanding of ultrafast demagnetization, information on…

The ultra-fast demagnetization of small iron clusters initiated by an intense optical excitation is studied with time-dependent spin density functional theory (TDSDFT). In particular we investigate the effect of the spin-orbit interaction…

Mesoscale and Nanoscale Physics · Physics 2016-07-27 Maria Stamenova , Jacopo Simoni , Stefano Sanvito

Excitation of a metallic ferromagnet such as Ni with an intensive femtosecond laser pulse causes an ultrafast demagnetization within approximately 300 fs. It was proposed that the ultrafast demagnetization measured in femtosecond…

Materials Science · Physics 2016-09-27 Ritwik Mondal , Marco Berritta , Karel Carva , Peter M. Oppeneer

Ultrafast demagnetization induced by femtosecond laser pulses in thin metallic layers is caused by the outflow of spin-polarized hot electron currents describable by the superdiffusive transport model. These laser-generated spin currents…

Mesoscale and Nanoscale Physics · Physics 2023-05-24 Pavel Baláž , Maciej Zwierzycki , Francesco Cosco , Karel Carva , Pablo Maldonado , Peter M. Oppeneer

Laser-induced ultrafast demagnetization is a phenomenon of utmost interest and attracts significant attention because it enables potential applications in ultrafast optoelectronics and spintronics. As a spin-orbit coupling assisted magnetic…

We analytically solve the {\it Non-Markovian} single electron spin dynamics due to hyperfine interaction with surrounding nuclei in a quantum dot. We use the equation-of-motion method assisted with a large field expansion, and find that…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Changxue Deng , Xuedong Hu

By correlating time- and angle-resolved photoemission and time-resolved transverse- magneto- optical Kerr effect measurements, both at extreme ultraviolet wavelengths, we uncover the universal nature of the ultrafast photoinduced magnetic…

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