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Related papers: Exploring dynamical magnetism with time-dependent …

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Perpendicular magnetic anisotropy (PMA) and low magnetic damping are the key factors for the free layer magnetization switching by spin transfer torque technique in magnetic tunnel junction devices. The magnetization precessional dynamics…

Materials Science · Physics 2015-05-15 B. Samantaray , Akhilesh K. Singh , A. Perumal , R. Ranganathan , P. Mandal

We explore the limitations and validity of semi-classically formulated spin equations of motion. Using a single-molecule magnet as a test model, we employ three qualitatively different approximation schemes. From a microscopic model, we…

Mesoscale and Nanoscale Physics · Physics 2017-12-13 Henning Hammar , Jonas Fransson

Most applications of time-dependent density-functional theory (TDDFT) use the adiabatic local-density approximation (ALDA) for the dynamical exchange-correlation potential Vxc(r,t). An exact (i.e., nonadiabatic) extension of the…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 C. A. Ullrich

We study a model quantum dot system in an external magnetic field by using both the spin-density-functional theory and the current-spin-density-functional theory. The theories are used with local approximations for the spin-density and the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 H. Saarikoski , E. Räsänen , S. Siljamäki , A. Harju , M. J. Puska , R. M. Nieminen

We consider the effect of potential disorder on magnetic properties of a two-dimensional metallic system (with conductance $g\gg 1$) when interaction in the triplet channel is so strong that the system is close to the threshold of the…

Disordered Systems and Neural Networks · Physics 2009-10-31 B. N. Narozhny , I. L. Aleiner , A. I. Larkin

The Hohenberg-Kohn theorem of density functional theory (DFT) for the case of electrons interacting with an external magnetic field (that couples to spin only) is examined in more detail than previously. A unexpected generalization is…

Strongly Correlated Electrons · Physics 2009-10-31 H. Eschrig , W. E. Pickett

A major challenge in using spin-flip time-dependent density functional theory (SF-TD-DFT) for spin-flip-down excitations is the presence of spin contamination. While several improved methods have been developed in the past, a simple and…

Chemical Physics · Physics 2025-11-24 Hewang Zhao , Zhendong Li

We give a brief account of recent developments in the theoretical understanding of the interaction between electric currents and inhomogeneous ferromagnetic order parameters. We start by discussing the physical origin of the spin torques…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Yaroslav Tserkovnyak , Arne Brataas , Gerrit E. W. Bauer

The phenomenological Landau-Lifshitz-Gilbert (LLG) equation of motion remains as the cornerstone of contemporary magnetisation dynamics studies, wherein the Gilbert damping parameter has been attributed to first-order relativistic effects.…

Other Condensed Matter · Physics 2018-06-28 Ritwik Mondal , Marco Berritta , Peter M. Oppeneer

A fully quantum mechanical description of the precessional damping of Pt/Co bilayer is presented in the framework of the Keldysh Green function approach using {\it ab initio} electronic structure calculations. In contrast to previous…

Mesoscale and Nanoscale Physics · Physics 2017-12-20 Farzad Mahfouzi , Jinwoong Kim , Nicholas Kioussis

The real-time electronic dynamics on material surfaces is critically important to a variety of applications. However, their simulations have remained challenging for conventional methods such as the time-dependent density-functional theory…

Chemical Physics · Physics 2015-06-16 Rulin Wang , Dong Hou , Xiao Zheng

Phenomenological approach is developed in the theory of spin-valve type ferromagnetic junctions to describe exchange switching by current flowing perpendicular to interfaces. Forward and backward current switching effects are described and…

Materials Science · Physics 2007-05-23 E. M. Epshtein , Yu. V. Gulyaev , P. E. Zilberman

A density-functional theory is developed based on the Maxwell--Schr\"odinger equation with an internal magnetic field in addition to the external electromagnetic potentials. The basic variables of this theory are the electron density and…

Chemical Physics · Physics 2018-01-17 Erik Tellgren

The application of methods of time-dependent density functional theory (TDDFT) to systems of qubits provided the interesting possibility of simulating an assigned Hamiltonian evolution by means of an auxiliary Hamiltonian having different…

Quantum Physics · Physics 2012-03-08 Diego de Falco , Dario Tamascelli

We formulate a time-dependent density-matrix functional theory (TDDMFT) approach for higher-order correlation effects like biexcitons in optical processes in solids based on the reduced two-particle density-matrix formalism within the…

Materials Science · Physics 2015-05-19 Volodymyr Turkowski , Carsten A. Ullrich , Talat S. Rahman , Michael N. Leuenberger

Damping mechanisms in magnetic systems determine the lifetime, diffusion and transport properties of magnons, domain walls, magnetic vortices, and skyrmions. Based on the phenomenological Landau-Lifshitz-Gilbert equation, here the effective…

Materials Science · Physics 2018-10-16 Levente Rózsa , Julian Hagemeister , Elena Y. Vedmedenko , Roland Wiesendanger

Within time-dependent density functional theory, combined with the Korringa-Kohn-Rostoker Green functions, we devise a real space method to investigate spin dynamics. Our scheme enables one to deduce the Coulomb potential which assures a…

Materials Science · Physics 2010-10-27 S. Lounis , A. T. Costa , R. B. Muniz , D. L. Mills

We study spin transport between a ferromagnet with time-dependent magnetization and a conducting carbon nanotube or quantum wire, modeled as a Luttinger liquid. The precession of the magnetization vector of the ferromagnet due for instance…

Strongly Correlated Electrons · Physics 2009-11-10 Cristina Bena , Leon Balents

The existence of a weak galactic magnetic field has been repeatedly confirmed by observational data. The origin of this field has not as yet been explained in a fully satisfactory way and represents one of the main challenges of the…

Astrophysics · Physics 2009-11-06 Alexander Schekochihin , Stanislav Boldyrev , Russell Kulsrud

A quantum mechanical model is used to derive a generalized Landau-Lifshitz equation for a magnetic moment, including fluctuations and dissipation. The model reproduces the Gilbert-Brown form of the equation in the classical limit. The…

Materials Science · Physics 2009-11-07 A. Rebei , G. J. Parker