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Related papers: Spin Dynamics of a Magnetic Antivortex

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Non-adiabatic contribution of environmental degrees of freedom yields effective inertia of spin in effective spin dynamics. In this paper, we study several aspects of the inertia of spin in metallic ferromagnets. (i) a concrete expression…

Mesoscale and Nanoscale Physics · Physics 2015-11-17 Toru Kikuchi , Gen Tatara

The dynamics of individual magnetic skyrmions confined in ultrathin film dots is studied theoretically. The systems considered are transition metal ferromagnets possessing perpendicular magnetic anisotropy and particular attention is given…

Scanning transmission x-ray microscopy is employed to investigate experimentally the reversal of the magnetic vortex core polarity in cylindrical Ni81Fe19 nanodisks triggered by two orthogonal monopolar magnetic field pulses with peak…

A spin wave theory explaining experimentally observed frequency splitting of dynamical excitations with azimuthal symmetry of a magnetic dot in a vortex ground state is developed. It is shown that this splitting is a result of the dipolar…

Materials Science · Physics 2010-02-03 Konstantin Y. Guslienko , Andrei N. Slavin , Vasyl Tiberkevich , Sang-Koog Kim

We found from analytical derivations and micromagnetic numerical simulations that there exist two distinct normal modes in apparently complex vortex gyrotropic motions in two dipolar-coupled magnetic nanodisks. The normal modes have…

Materials Science · Physics 2015-05-27 Ki-Suk Lee , Hyunsung Jung , Dong-Soo Han , Sang-Koog Kim

Recently, remarkable anti-glitch and glitch accompanied by bright radio bursts of the Galactic magnetar SGR J1935+2154 were discovered. These two infrequent temporal coincidences between the glitch/anti-glitch and the fast radio burst…

High Energy Astrophysical Phenomena · Physics 2023-06-07 Qin Wu , Zhen-Yin Zhao , F. Y. Wang

Time-resolved X-ray microscopy is used to image the influence of alternating high-density currents on the magnetization dynamics of ferromagnetic vortices. Spin-torque induced vortex gyration is observed in micrometer-sized permalloy…

The dynamics of vortex states in confined geometries like thin-film disks are characterized by a sub-GHz gyration, representing the damped oscillatory motion of the vortex core about the disk center. It has recently been shown that…

Mesoscale and Nanoscale Physics · Physics 2025-07-29 Gauthier Philippe , Joo-Von Kim

Performance of magnetoresistive sensors is today mainly limited by their 1/f low-frequency noise. Here, we study this noise component in vortex-based TMR sensors. We compare the noise level in different magnetization configurations of the…

The switching of a vortex core of a single disk in an array of a multilayer system is investigated by micromagnetic simulation. We found that the perpendicular uniaxial anisotropy (PUA) decreases the frequencies of the azimuthal mode in…

Mesoscale and Nanoscale Physics · Physics 2018-05-09 H. Vigo-Cotrina , A. P. Guimarães

We use a sensitive magneto-optical microscopy technique to image the magnetization response of micron-scale ferromagnetic disks to changes in applied magnetic field. This differential technique relies on a modulated applied magnetic field…

Mesoscale and Nanoscale Physics · Physics 2015-12-09 Robert Badea , Johnathon A. Frey , Jesse Berezovsky

The influence of a strain-induced uniaxial magnetoelastic anisotropy on the magnetic vortex core dynamics in microstructured magnetostrictive Co$_{40}$Fe$_{40}$B$_{20}$ elements was investigated with time-resolved scanning transmission…

We present an experimental investigation of radial spin-wave modes in magnetic nano-disks with a vortex ground state. The spin-wave amplitude was measured using a frequency-resolved magneto optical network analyzer, allowing for…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 M. Helsen , A. Gangwar , J. De Clercq , A. Vansteenkiste , B. Van Waeyenberge

We study the magnetization dynamics in a nanocontact magnetic vortex oscillators as function of temperature. Low temperature experiments reveal that the dynamics at low and high currents differ qualitatively. At low currents, we excite a…

We demonstrate the controlled generation and annihilation of (anti)skyrmions with tunable chirality in magnetic heterostructures by means of micromagnetic simulations. By making use of magnetic (anti)vortices in patterned ferromagnetic…

Mesoscale and Nanoscale Physics · Physics 2022-07-26 Sabri Koraltan , Claas Abert , Florian Bruckner , Michael Heigl , Manfred Albrecht , Dieter Suess

Topological orbital moments can arise in non-coplanar spin structures even in the absence of spin-orbit coupling and a net topological orbital magnetization occurs for the triple-Q state and for isolated skyrmions. For atomic-scale skyrmion…

This chapter describes spin-wave excitations in nanosized dots and rings in the presence of the vortex state. The special attention is paid to the manifestation of the competition between exchange and dipolar interactions in the spin-wave…

Mesoscale and Nanoscale Physics · Physics 2017-03-21 Sławomir Mamica

We consider the radial migration of vortices in two-dimensional isothermal gaseous disks. We find that a vortex core, orbiting at the local gas velocity, induces velocity perturbations that propagate away from the vortex as density waves.…

Earth and Planetary Astrophysics · Physics 2015-05-20 S. -J. Paardekooper , G. Lesur , J. C. B. Papaloizou

Magnetization reversals through the formation of vortex state and the rotation of onion state are two processes with comparable probabilities for symmetric magnetic nanorings with radius of about 50 nanometers. This magnetic bistability is…

Materials Science · Physics 2009-11-11 F. Q. Zhu , G. W. Chern , O. Tchernyshyov , X. C. Zhu , J. G. Zhu , C. L. Chien

It is shown that under the action of rotating magnetic field an immobile vortex, contrary to a general belief, can nucleate a vortex-antivortex pair and switch its polarity. Two different kinds of OOMMF micromagnetic modeling are used: (i)…

Strongly Correlated Electrons · Physics 2011-04-13 Volodymyr P. Kravchuk , Yuri Gaididei , Denis D. Sheka