Related papers: Bistability of vortex core dynamics in a single pe…
Finite-element micromagnetic simulations are employed to study the chiral symmetry breaking of magnetic vortices, caused by the surface roughness of thin-film magnetic structures. An asymmetry between vortices with different core…
Vortices are topological objects formed in coherent nonlinear systems. As such they are studied in a wide number of physical systems and promise applications in information storage, processing, and communication. In semiconductor…
To verify the exact underlying mechanism of ultrafast vortex-core reversal as well as the vortex state stability we conducted numerical calculations of the dynamic evolution of magnetic vortices in Permalloy cylindrical nanodots under an…
We demonstrate a non-linear interference due to an active 'dual frequency' excitation of both, the sub-GHz vortex gyromode and multi-GHz magneto-static spin waves in ferromagnetic micrometer sized platelets in the vortex state. When the…
In this paper, using micromagnetic simulations, we investigate the stress-induced frequency tunability of double-vortex nano-oscillators comprising magnetostrictive and non-magnetostrictive ferromagnetic layers separated vertically by a…
Topological magnetic textures are of great interest in various scientific and technological fields. To allow for precise control of nanoscale magnetism, it is of great importance to understand the role of intrinsic defects in the host…
A magnetic vortex core in a ferromagnetic circular nanodot has a resonance frequency originating from the confinement of the vortex core. By the micromagnetic simulation including the spin-transfer torque, we show that the vortex core can…
Magnetic vortices are characterized by the senses of in-plane magnetization chirality and by the polarity of the vortex core. The electrical control of vortex polarity and chirality is highly demanded not only for fundamental understanding…
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…
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…
Micromagnetic simulations are used to study a spin-torque vortex oscillator excited by an out-of-plane dc current. The vortex core gyration amplitude is confined between two orbits due to periodical vortex core polarity reversals. The upper…
We consider a nanodisk possessing two coupled materials with different ferromagnetic exchange constant. The common border line of the two media passes at the disk center dividing the system exactly in two similar half-disks. The vortex core…
Spin-orbit-torque-driven dynamics have recently gained interest in the field of magnetism due to the reduced requirement of current densities and an increase in efficiency, as well as the ease of implementation of different devices and…
We demonstrate a novel method allowing the study of the magnetic state dynamics of a single nanoparticle by means of electron transport measurements. Elliptical 550 nm x 240 nm permalloy nanoparticles are wired with non-magnetic leads for…
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…
A two-parameter analytical model of the magnetic vortex in a thin disk of soft magnetic material is constructed. The model is capable of describing the change in evolution of net vortex state magnetization and of core position when the…
Because of its stability, the polarity of a magnetic vortex core (VC) is a candidate for binary data storage. Switching can be accomplished, e.g, by driving the VC above a critical velocity $v_c$. Here, we report on controlled and repeated…
For a circular magnetic nanodot in a vortex ground state we study how the critical velocity $v_c$ of the vortex core reversal depends on the magnitude $H$ of a bias magnetic field applied perpendicularly to the dot plane. We find that,…
Magnetic nanoparticles play a crucial role in different fields such as biomedicine or information and quantum technologies. These applications require nanoparticles with a single, well-defined energy minimum, free of metastable states, and…
We study the dynamics of a vortex state nanodisk due to a dc spin current, perpendicular to the disk plane. The irreversible switching of the vortex polarity takes place above some threshold current. The detailed description of these…