Journal ArticleDOI
Laser-Induced Demagnetization at Ultrashort Time Scales: Predictions of TDDFT
TLDR
It is demonstrated that this form of demagnetization is a two-step process: excitation of a fraction of electrons followed by spin-flip transitions mediated by spin–orbit coupling of the remaining localized electrons and it is possible to control the moment loss by tunable laser parameters, including frequency, duration, and intensity.Abstract:
Time-dependent density functional theory (TDDFT) is implemented in an all electron solid-state code for the case of fully unconstrained noncollinear spins. We use this to study intense, short, laser pulse-induced demagnetization in bulk Fe, Co, Ni and find that demagnetization can take place on time scales of <20 fs. It is demonstrated that this form of demagnetization is a two-step process: excitation of a fraction of electrons followed by spin-flip transitions mediated by spin–orbit coupling of the remaining localized electrons. We further show that it is possible to control the moment loss by tunable laser parameters, including frequency, duration, and intensity.read more
Citations
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Journal ArticleDOI
Perspective: Fundamental aspects of time-dependent density functional theory.
TL;DR: This Perspective looks back to some of these developments, reports on some recent progress and current challenges for functionals, and speculates on future directions to improve the accuracy of approximations used in this relatively young theory.
Journal ArticleDOI
Laser-Induced Intersite Spin Transfer.
TL;DR: Laser pulses induce spin-selective charge flow that is universally applicable to AFM, FM, and ferri-magnets in both multilayer and bulk geometry and provide three rules that encapsulate early-time magnetization dynamics of multisub-lattice systems.
Journal ArticleDOI
Critical behavior within 20 fs drives the out-of-equilibrium laser-induced magnetic phase transition in nickel
Phoebe Tengdin,Wenjing You,Cong Chen,Xun Shi,Dmitriy Zusin,Yingchao Zhang,Christian Gentry,Adam Blonsky,Mark W. Keller,Peter M. Oppeneer,Henry C. Kapteyn,Zhensheng Tao,Margaret M. Murnane +12 more
TL;DR: In this paper, the authors connect the out-of-equilibrium material behavior to the strongly coupled equilibrium behavior and uncover a new time scale in the process of ultrafast demagnetization.
Journal ArticleDOI
Ultrafast optically induced spin transfer in ferromagnetic alloys
Moritz Hofherr,S. Häuser,J. K. Dewhurst,Phoebe Tengdin,S. Sakshath,Hans T. Nembach,Hans T. Nembach,Sebastian T. Weber,Justin M. Shaw,Thomas J. Silva,Henry C. Kapteyn,Mirko Cinchetti,Baerbel Rethfeld,Margaret M. Murnane,Daniel Steil,Benjamin Stadtmüller,Sangeeta Sharma,Martin Aeschlimann,Stefan Mathias +18 more
TL;DR: The experimental findings are fully supported by time-dependent density functional theory simulations and suggest the possibility of coherently controlling spin dynamics on subfemtosecond time scales, i.e., the birth of the research area of attomagnetism.
Journal ArticleDOI
The Ultrafast Einstein-De Haas Effect
Christian Dornes,Yves Acremann,Matteo Savoini,M. Kubli,Martin J. Neugebauer,Elsa Abreu,Lucas Huber,Gabriel Lantz,C. A. F. Vaz,Henrik T. Lemke,Elisabeth M. Bothschafter,Michael Porer,Vincent Esposito,Laurenz Rettig,Laurenz Rettig,Michele Buzzi,Michele Buzzi,A. Alberca,Yoav William Windsor,Yoav William Windsor,Paul Beaud,Urs Staub,Diling Zhu,Sanghoon Song,James M. Glownia,Steven L. Johnson,Steven L. Johnson +26 more
TL;DR: In this article, it was shown that a large fraction of the angular momentum associated with the aligned electron spins in a ferromagnet can be converted to mechanical angular momentum by reversing the direction of magnetisation using an external magnetic field.
References
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Journal ArticleDOI
Density-Functional Theory for Time-Dependent Systems
Erich Runge,E. K. U. Gross +1 more
TL;DR: In this article, a time-dependent version of density functional theory was proposed to deal with the non-perturbative quantum mechanical description of interacting many-body systems moving in a very strong timedependent external field.
Journal ArticleDOI
Ultrafast spin dynamics in ferromagnetic nickel.
TL;DR: The relaxation processes of electrons and spins systems following the absorption of femtosecondoptical pulses in ferromagnetic nickel have been studied using optical and magneto-optical pump-probetechniques and the experimental results are adequately described by a model including three interacting reservoirs.
Journal ArticleDOI
Ultrafast optical manipulation of magnetic order
TL;DR: In this article, the authors review the progress in this field of laser manipulation of magnetic order in a systematic way and show that the polarization of light plays an essential role in the manipulation of the magnetic moments at the femtosecond time scale.
Journal ArticleDOI
Explaining the paradoxical diversity of ultrafast laser-induced demagnetization
B Bert Koopmans,Gregory Malinowski,F. Dalla Longa,D. Steiauf,M. Fähnle,T. Roth,Mirko Cinchetti,Martin Aeschlimann +7 more
TL;DR: It is shown that a model based on electron-phonon-mediated spin-flip scattering explains both timescales on equal footing and concludes that the ultrafast magnetization dynamics can be well described disregarding highly excited electronic states, merely considering the thermalized electron system.
Journal ArticleDOI
Superdiffusive Spin Transport as a Mechanism of Ultrafast Demagnetization
TL;DR: A semiclassical model for femtosecond laser-induced demagnetization due to spin-polarized excited electron diffusion in the superdiffusive regime is proposed and it is shown that this mechanism accounts for the experimentally observed demagnetsization within 200 fs in Ni, without the need to invoke any angular momentum dissipation channel.