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Related papers: Insights into ultrafast demagnetization in pseudo-…

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Reducing energy dissipation while increasing speed in computation and memory is a long-standing challenge for spintronics research. In the last 20 years, femtosecond lasers have emerged as a tool to control the magnetization in specific…

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

Tunnelling density of states in the vicinity of Fermi level of a two-dimensional electron gas subjected to an external parallel and zeroth magnetic field is calculated. It reveals a pseudo-gap recently observed in the experiments. The gap…

Strongly Correlated Electrons · Physics 2015-06-24 V. Vyurkov , A. Vetrov , V. Ryzhii

We present a dynamical model that successfully explains the observed time evolution of the magnetization in diluted magnetic semiconductor quantum wells after weak laser excitation. Based on the pseudo-fermion formalism and a second order…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 O. Morandi , P. -A. Hervieux , G. Manfredi

Exact calculated time evolutions in the framework of a many-electron model of itinerant magnetism provide new insights into the laser-induced ultrafast demagnetization observed in ferromagnetic (FM) transition metal thin films. The…

Strongly Correlated Electrons · Physics 2015-11-25 W. Töws , G. M. Pastor

We report on optically induced, ultrafast magnetization dynamics in the Heusler alloy $\mathrm{Co_{2}FeAl}$, probed by time-resolved magneto-optical Kerr effect. Experimental results are compared to results from electronic structure theory…

Carrying a large, pure spin magnetic moment of 7 $\mu$bohr/atom in the half-filled 4f shell, divalent europium is an outstanding element for assembling novel magnetic devices in which a two-dimensional electron gas (2DEG) is polarized due…

The ultimate control of magnetic states of matter at femtosecond (or even faster) timescales defines one of the most pursued paradigm shifts for future information technology. In this context, ultrafast laser pulses developed into extremely…

Mesoscale and Nanoscale Physics · Physics 2022-03-15 Hanan Hamamera , Filipe Souza Mendes Guimarães , Manuel dos Santos Dias , Samir Lounis

Spin and orbital angular momenta are two intrinsic properties of an electron and are responsible for the physics of a solid. How the spin and orbital evolve with respect to each other on several hundred femtoseconds is largely unknown, but…

Materials Science · Physics 2021-06-25 G. P. Zhang , Mingqiang Gu , Y. H. Bai , T. L. Jenkins , Thomas F. George

We elucidate the itinerant ferromagnetism of a dipolar Fermi gas with a Raman-induced spin-orbit coupling by investigating the exotic phase diagrams at zero and finite temperature. It is revealed that the dipolar interaction along with…

Quantum Gases · Physics 2022-06-15 Xue-Jing Feng , Xing-Dong Zhao , Wu-Ming Liu

The spin-flip (SF) Eliashberg function is calculated from first-principles for ferromagnetic Ni to accurately establish the contribution of Elliott-Yafet electron-phonon SF scattering to Ni's femtosecond laser-driven demagnetization. This…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 K. Carva , M. Battiato , P. M. Oppeneer

We demonstrate demagnetization cooling of a gas of ultracold $^{52}$Cr atoms. Demagnetization is driven by inelastic dipolar collisions which couple the motional degrees of freedom to the spin degree. By that kinetic energy is converted…

Other Condensed Matter · Physics 2015-06-25 M. Fattori , T. Koch , S. Goetz , A. Griesmaier , S. Hensler , J. Stuhler , T. Pfau

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

As a fundamental property of the electron, the spin plays a decisive role in the electronic structure of matter from solids to molecules and atoms, e.g. causing magnetism. Yet, despite its importance, the spin dynamics of electrons released…

Femtosecond laser induced ultrafast magnetization dynamics have been studied in multisublattice CoxDy1-x alloys. By performing element and time-resolved X-ray spectroscopy, we distinguish the ultrafast quenching of Co3d and Dy4f magnetic…

Materials Science · Physics 2017-10-16 T. Ferte , N. Bergeard , L. Le Guyader , M. Hehn , G. Malinowski , E. Terrier , E. Otero , K. Holldack , N. Pontius , C. Boeglin

Employing electron spin instead of charge to develop spintronic devices holds the merits of low-power consumption in information technologies. Meanwhile, the demand for increasing speed in spintronics beyond current CMOS technology has…

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…

Laser radiation incident on a ferromagnetic sample produces excited electrons and currents whose spin polarization must not be aligned with the magnetization -- an effect due to spin-orbit coupling that is ubiquitous in spin- and…

Materials Science · Physics 2023-11-03 Oliver Busch , Franziska Ziolkowski , Ingrid Mertig , Jürgen Henk

A model is developed with the aim of analyzing interacting superparamagnets. Model is built from magnetic dipolar interaction and demagnetizing mean field concepts. A useful expression for effective demagnetizing factors is achieved, which…

Mesoscale and Nanoscale Physics · Physics 2017-04-19 F. H. Sánchez , P. Mendoza Zélis , M. L. Arciniegas , G. A. Pasquevich , M. B. Fernández van Raap

From the study of long-range-interacting systems to the simulation of gauge fields, open-shell Lanthanide atoms with their large magnetic moment and narrow optical transitions open novel directions in the field of ultracold quantum gases.…