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Burkard Hillebrands - One of the best experts on this subject based on the ideXlab platform.

  • Suppression of magnetic-Field Pulse-induced magnetization precession by Pulse tailoring
    Applied Physics Letters, 2000
    Co-Authors: M Bauer, R. Lopusnik, Jürgen Fassbender, Burkard Hillebrands
    Abstract:

    Short magnetic-Field Pulses may be used in the near future to change the magnetization state in magnetic storage devices. In order to minimize the time required for this process, and thus to maximize the switching speed of such devices, the magnetization precession after the termination of the magnetic-Field Pulse needs to be suppressed to a maximum degree. It is demonstrated experimentally that the appropriate adjustment of the Field Pulse parameters may lead to a full suppression of the magnetization precession immediately upon termination of the Field Pulse.

  • Magnetization reversal in ultrashort magnetic Field Pulses
    Journal of Magnetism and Magnetic Materials, 2000
    Co-Authors: M Bauer, R. Lopusnik, Jürgen Fassbender, Burkard Hillebrands
    Abstract:

    We report the switching properties of a thin magnetic film subject to an ultrashort, laterally localized magnetic Field Pulse, obtained by numerical investigations. The magnetization distribution in the film is calculated on a grid assuming Stoner-like coherent rotation within the grid square size. Perpendicularly and in-plane magnetized films exhibit a magnetization reversal due to a 4 ps magnetic Field Pulse. Outside the central region the Pulse duration is short compared to the precession period. In this area the evolution of the magnetization during the Field Pulse does not depend strongly on magnetic damping and/or Pulse shape. However, the final magnetization distribution is affected by the magnetic damping. Although the Pulse duration is short compared to the precession period, the time needed for the relaxation of the magnetization to the equilibrium state is rather large. The influence of the different magnetic anisotropy contributions and the magnetic damping parameter enters into the magnetization reversal process. Comparing the case of perpendicular anisotropy with different kinds of in-plane anisotropies, a principal difference is found due to the symmetry of the shape anisotropy with respect to the anisotropy in question.

  • Successful suppression of magnetization precession after short Field Pulses
    IEEE Transactions on Magnetics, 2000
    Co-Authors: M Bauer, R. Lopusnik, Jürgen Fassbender, Burkard Hillebrands, H. Dötsch
    Abstract:

    For the next generation of high data rate magnetic recording above 1 Gbit/s, a better understanding of the switching processes for both recording heads and media will be required, In order to maximize the switching speed for such devices, the magnetization precession after the magnetic Field Pulse termination needs to be suppressed to a maximum degree. It is demonstrated experimentally for ferrite films that the appropriate adjustment of the Field Pulse parameters and/or the static applied Field may lead to a full suppression of the magnetization precession immediately upon termination of the Field Pulse. The suppression is explained by taking into account the actual direction of the magnetization with respect to the static Field direction at the Pulse termination.

Gregory W. Donohoe - One of the best experts on this subject based on the ideXlab platform.

  • Dynamics of magnetic vortex core switching in Fe nanodisks by applying in-plane magnetic Field Pulse
    Journal of Applied Physics, 2007
    Co-Authors: Q. F. Xiao, Byoung-chul Choi, J. Rudge, Yang-ki Hong, E. Girgis, J. Kolthammer, Gregory W. Donohoe
    Abstract:

    We investigated the influence of the magnetic Field Pulse parameters and the size of the Fe element to the vortex core switching by micromagnetic modeling. When the magnetic Field Pulse with an appropriate strength and duration is applied to 30nm thick Fe circular disks with diameters between 100nm and 1μm, the vortex configuration is perturbed away from the equilibrium state, and the circular symmetric distribution of the in-plane magnetization around the vortex core deforms. This leads to the creation of a new vortex core with the opposite polarity and an antivortex. With increasing time, the vortex-antivortex pair annihilates. As a result of the annihilation, a single vortex core with opposite polarity remains and a vortex core switch is realized. The process of core switching, however, strongly depends on the amplitude and duration of the magnetic Pulse.

  • Effect of a magnetic Field Pulse on ultrafast magnetization reversal in a submicron elliptical Permalloy thin film
    Journal of Applied Physics, 2007
    Co-Authors: Q. F. Xiao, Byoung-chul Choi, J. Rudge, Yang-ki Hong, Gregory W. Donohoe
    Abstract:

    The characteristics of a magnetic Field Pulse, its magnitude, direction, and rise and fall time on the mechanism of ultrafast magnetization reversal have been studied by micromagnetic simulations. An elliptically shaped, Permalloy thin film, having dimensions of 400nm long axis, 112nm short axis, and 3.2nm, thickness, was considered. A plot of the magnetic Field Pulse components describes three types of reversal behaviors, quasicoherent, incoherent, and nonreversal. The optimum magnetic Field Pulse for the suppression of magnetization ringing is found in the incoherent precession area by finding the lowest remanent total energy at the moment the Pulse is cut off. The rise and fall time of the Pulse has a significant effect on the reversal behavior only in the incoherent precession region. In this region, whether a reversal can occur depends on the rise time of the Pulse. Extending the rise and fall time of the Pulse, in the noncoherent rotation region, does not lead to a clear change of the remanent total...

M Bauer - One of the best experts on this subject based on the ideXlab platform.

  • Suppression of magnetic-Field Pulse-induced magnetization precession by Pulse tailoring
    Applied Physics Letters, 2000
    Co-Authors: M Bauer, R. Lopusnik, Jürgen Fassbender, Burkard Hillebrands
    Abstract:

    Short magnetic-Field Pulses may be used in the near future to change the magnetization state in magnetic storage devices. In order to minimize the time required for this process, and thus to maximize the switching speed of such devices, the magnetization precession after the termination of the magnetic-Field Pulse needs to be suppressed to a maximum degree. It is demonstrated experimentally that the appropriate adjustment of the Field Pulse parameters may lead to a full suppression of the magnetization precession immediately upon termination of the Field Pulse.

  • Magnetization reversal in ultrashort magnetic Field Pulses
    Journal of Magnetism and Magnetic Materials, 2000
    Co-Authors: M Bauer, R. Lopusnik, Jürgen Fassbender, Burkard Hillebrands
    Abstract:

    We report the switching properties of a thin magnetic film subject to an ultrashort, laterally localized magnetic Field Pulse, obtained by numerical investigations. The magnetization distribution in the film is calculated on a grid assuming Stoner-like coherent rotation within the grid square size. Perpendicularly and in-plane magnetized films exhibit a magnetization reversal due to a 4 ps magnetic Field Pulse. Outside the central region the Pulse duration is short compared to the precession period. In this area the evolution of the magnetization during the Field Pulse does not depend strongly on magnetic damping and/or Pulse shape. However, the final magnetization distribution is affected by the magnetic damping. Although the Pulse duration is short compared to the precession period, the time needed for the relaxation of the magnetization to the equilibrium state is rather large. The influence of the different magnetic anisotropy contributions and the magnetic damping parameter enters into the magnetization reversal process. Comparing the case of perpendicular anisotropy with different kinds of in-plane anisotropies, a principal difference is found due to the symmetry of the shape anisotropy with respect to the anisotropy in question.

  • Successful suppression of magnetization precession after short Field Pulses
    IEEE Transactions on Magnetics, 2000
    Co-Authors: M Bauer, R. Lopusnik, Jürgen Fassbender, Burkard Hillebrands, H. Dötsch
    Abstract:

    For the next generation of high data rate magnetic recording above 1 Gbit/s, a better understanding of the switching processes for both recording heads and media will be required, In order to maximize the switching speed for such devices, the magnetization precession after the magnetic Field Pulse termination needs to be suppressed to a maximum degree. It is demonstrated experimentally for ferrite films that the appropriate adjustment of the Field Pulse parameters and/or the static applied Field may lead to a full suppression of the magnetization precession immediately upon termination of the Field Pulse. The suppression is explained by taking into account the actual direction of the magnetization with respect to the static Field direction at the Pulse termination.

Ksenya A Makarova - One of the best experts on this subject based on the ideXlab platform.

  • analytical wave function of an atomic electron under the action of a powerful ultrashort electromagnetic Field Pulse
    Optics Letters, 2019
    Co-Authors: D N Makarov, M K Eseev, Ksenya A Makarova
    Abstract:

    The interaction of atomic systems with high-power ultrashort electromagnetic Field Pulses (USPs) is currently the subject of many theoretical and experimental studies. However, a wave function has yet to be developed for the atomic electron located in such Fields, including relativistic Fields. In this Letter, an equation is obtained that is similar to the Schrodinger equation for the Fields under consideration, but which takes into the account relativistic effects in powerful spatially inhomogeneous Fields of USPs. Using the sudden disturbance approximation, an exact solution of the resulting equation is obtained in the form of an analytical wave function which is suitable for any type and form of ultrashort Pulse, and which takes into account its magnetic component. It is shown that the obtained wave function satisfies the necessary completeness condition in quantum mechanics.

Yoshinobu Nakatani - One of the best experts on this subject based on the ideXlab platform.

  • Switching of magnetic vortex core in elliptical disks by nanosecond Field Pulses
    Applied Physics Express, 2014
    Co-Authors: Keisuke Yamada, Tomonori Sato, Yoshinobu Nakatani, Shinya Kasai, Daichi Chiba, Kensuke Kobayashi, André Thiaville, Teruo Ono
    Abstract:

    We report the switching of a magnetic vortex core in ferromagnetic elliptical disks induced by a nanosecond Field Pulse. We show that the switching probability depends on both the duration and amplitude of the Field Pulse. The minimum magnetic Field required for the core switching depends also on the ellipticity of the disk. Micromagnetic simulations reproduce this behavior and reveal that there are two mechanisms of the core switching.

  • Switching of the Magnetic Vortex Core in a Pac-man Disk using a Single Field-Pulse
    Applied Physics Express, 2014
    Co-Authors: Tomonori Sato, Keisuke Yamada, Yoshinobu Nakatani
    Abstract:

    We report on the switching of the magnetic vortex core in a Pac-man disk using a magnetic Field Pulse, investigated via micromagnetic simulations. The minimum core switching Field is reduced by 72 % compared to that of a circular disk with the same diameter and thickness. However, the core switches irregularly with respect to both the Field Pulse amplitude and duration. This irregularity is induced by magnetization oscillations which arise due to excitation of the spin waves when the core annihilates. We show that the core switching can be controlled with the assist magnetic Field and by changing the waveform.