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Related papers: Super-Diffusive Spin-Transport as a Mechanism of U…

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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

Ultrafast demagnetization of magnetic layers pumped by a femtosecond laser pulse is accompanied by a nonthermal spin-polarized current of hot electrons. These spin currents are studied here theoretically in a spin valve with noncollinear…

Mesoscale and Nanoscale Physics · Physics 2018-02-26 Pavel Baláž , Martin Žonda , Karel Carva , Pablo Maldonado , Peter M. Oppeneer

We theoretically investigate laser-induced spin transport in metallic magnetic heterostructures using an effective spin transport description that treats itinerant electrons and thermal magnons on an equal footing. Electron-magnon…

Mesoscale and Nanoscale Physics · Physics 2022-04-27 Maarten Beens , Rembert A. Duine , Bert Koopmans

Experimental observations of the ultrafast (less than 50 fs) demagnetization of Ni have so far defied theoretical explanations particularly since its spin-flipping time is much less than that resulting from spin-orbit and electron-lattice…

Strongly Correlated Electrons · Physics 2020-07-08 Shree Ram Acharya , Volodymyr Turkowski , Guo-ping Zhang Talat S. Rahman

The injection of spin currents in semiconductors is one of the big challenges of spintronics. Motivated by the ultrafast demagnetisation and spin injection into metals, we propose an alternative femtosecond route based on the laser…

Materials Science · Physics 2016-05-25 M. Battiato , K. Held

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

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…

An ultrafast spin current can be induced by femtosecond laser excitation in a ferromagnetic (FM) thin film in contact with a nonmagnetic (NM) metal. The propagation of an ultrafast spin current into NM metal has recently been found in…

Mesoscale and Nanoscale Physics · Physics 2021-12-15 Wen-Tian Lu , Zhe Yuan

We examine a modified drift-diffusion formalism to describe spin transport near an ultrathin magnet whose thickness is similar to or less than the spin dephasing length. Most of the previous theories on spin torque assume the transverse…

Mesoscale and Nanoscale Physics · Physics 2019-06-19 Kyoung-Whan Kim

A systematic investigation of spin injection behavior in Au/FM (FM = Fe and Ni) multilayers is performed using the superdiffusive spin transport theory. By exciting the nonmagnetic layer, the laser-induced hot electrons may transfer spin…

Mesoscale and Nanoscale Physics · Physics 2023-11-20 Wen-Tian Lu , Zhe Yuan , Xiaohong Xu

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…

Manipulation of magnetic domain walls via a helicity-independent laser pulse has recently been experimentally demonstrated and various physical mechanisms leading to domain wall dynamics have been discussed. Spin-dependent superdiffusive…

Mesoscale and Nanoscale Physics · Physics 2020-05-20 Pavel Baláž , Karel Carva , Ulrike Ritzmann , Pablo Maldonado , Peter M. Oppeneer

We derive a drift-diffusion equation for spin polarization in semiconductors by consistently taking into account electric-field effects and nondegenerate electron statistics. We identify a high-field diffusive regime which has no analogue…

Materials Science · Physics 2009-11-07 Z. G. Yu , M. E. Flatte

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 theory of spin-polarized electron transport in ferromagnet-semiconductor heterostructures, based on a unified semiclassical description of ballistic and diffusive transport in semiconductors, is outlined. The aim is to provide a framework…

Materials Science · Physics 2007-05-23 R. Lipperheide , U. Wille

Laser-induced femtosecond demagnetization, femtomagnetism, offers a potential route to develop faster magnetic storage devices. It is generally believed that the traditional spin-wave theory, which is developed for thermally driven slow…

Materials Science · Physics 2019-12-05 G. P. Zhang , M. Murakami , Y. H. Bai , Thomas F. George , X. S. Wu

We discuss a joint microscopic theory for the laser-induced magnetization dynamics and spin transport in magnetic heterostructures based on the $s$-$d$ interaction. Angular momentum transfer is mediated by scattering of itinerant $s$…

Mesoscale and Nanoscale Physics · Physics 2020-09-24 Maarten Beens , Rembert A. Duine , Bert Koopmans

We study a recently discussed XX spin chain with non-local dephasing [arXiv:2310.03069] in a steady-state boundary-driven setting, confirming superdiffusive magnetization transport in the thermodynamic limit. The emergence of superdiffusion…

Strongly Correlated Electrons · Physics 2024-02-07 Marko Znidaric

We follow for the first time the evolution of the spin and orbital angular momentum of a thin Ni film during ultrafast demagnetization, by means of x-ray magnetic circular dichroism. Both components decrease with a 130 +/- 40 fs time…

Materials Science · Physics 2010-04-07 C. Stamm , N. Pontius , T. Kachel , M. Wietstruk , H. A. Dürr

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
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