Related papers: Current- and field-driven magnetic antivortices
In experiments the distinction between spin-torque and Oersted-field driven magnetization dynamics is still an open problem. Here, the gyroscopic motion of current- and field-driven magnetic vortices in small thin-film elements is…
A magnetic vortex occurs as an equilibrium configuration in thin ferromagnetic platelets of micron and sub-micron size and is characterised by an in-plane curling magnetisation. At the centre, a magnetic singularity is avoided by an…
We here experimentally demonstrate that coupled gyration modes can be resonantly excited primarily by the ac current in a pair of ferromagnetic disks with varied separating distance. The sole gyrotropic mode clearly splits into a higher and…
We study vortex pattern formation in thin ferromagnetic films under the action of strong spin-polarized currents. Considering the currents which are polarized along the normal of the film plane, we determine the critical current above which…
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…
A vortex-antivortex dipole can be generated due to current with in-plane spin-polarization, flowing into a magnetic element, which then behaves as a spin transfer oscillator. Its dynamics is analyzed using the Landau-Lifshitz equation…
We investigate vortex configuration in antiferromagnetic thin discs. It is shown that the vortex acquires oscillatory dynamics with well-defined amplitude and frequency which may be controlled on demand by an alternating spin polarized…
Micron-sized magnetic platelets in the flux closed vortex state are characterized by an in-plane curling magnetization and a nanometer-sized perpendicularly magnetized vortex core. Having the simplest non-trivial configuration, these…
We observe the dynamics of a single magnetic vortex in the presence of a random array of pinning sites. At low excitation amplitudes, the vortex core gyrates about its equilibrium position with a frequency that is characteristic of a single…
We investigate the gyrotropic motion of the magnetic vortex core in a chain of a few micron-sized Permalloy disks by electrical resistance measurement with amplitude-modulated magnetic field. We observe a distinctive splitting of the…
The current-induced resonant excitation of a magnetic vortex core is investigated by means of analytical and micromagnetic calculations. We find that the radius and the phase shift of the resonant motion are not correctly described by the…
We report on a study of the dynamics of a magnetic antivortex in a submicron, asteroid shaped, permalloy ferromagnet using micromagnetic simulations. As with vortex states in disk and square geometries, a gyrotropic mode was found in which…
The spin dynamics are calculated for a model system consisting of magnetically soft, layered nanomagnets, in which two ferromagnetic (F) cylindrical dots, each with a magnetic vortex ground state, are separated by a non-magnetic spacer (N).…
We consider a thin superconducting film with a magnetic dot with permanent magnetization (normal to the film) placed on it by a method based on London-Maxwell equations. For sufficiently high dot magnetization a single vortex appears in the…
Spin textures that are not readily available in the domain structures of continuous magnetic thin films can be stabilized when patterned to micro/nano scales due to the dominant effect of dipolar magnetic interactions. Fabrication of such…
In a thin magnetic nanostripe, an anti-vortex nucleates inside a moving domain wall when driven by an in-plane magnetic field greater than the so-called Walker field. The nucleated anti-vortex must cross the width of the nanostripe before…
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…
In this letter we address the vortex core dynamics involved in gyration excitation and damping change by out-of-plane oscillating magnetic fields. When the vortex core is at rest under the effect of in-plane bias magnetic fields, the spin…
We report magnetoresistance measurements through Nb films having a periodic thickness modulation. The cylinder shaped large-thickness regions of the sample, which form a square lattice, act as repulsive centers for the superconducting…
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…