English

Magnetization oscillations by vortex-antivortex dipoles

Mesoscale and Nanoscale Physics 2015-06-17 v1

Abstract

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 including a Slonczewski spin-torque term. We establish that the vortex dipole is set in steady state rotational motion due to the interaction between the vortices, while an external in-plane magnetic field can tune the frequency of rotation. The rotational motion is linked to the nonzero skyrmion number of the dipole. The spin-torque acts to stabilize the vortex dipole at a definite vortex-antivortex separation distance. In contrast to a free vortex dipole, the rotating pair under spin-polarized current is an attractor of the motion, therefore a stable state. Three types of vortex-antivortex pairs are obtained as we vary the external field and spin-torque strength. We give a guide for the frequency of rotation based on analytical relations.

Keywords

Cite

@article{arxiv.1308.4805,
  title  = {Magnetization oscillations by vortex-antivortex dipoles},
  author = {Stavros Komineas},
  journal= {arXiv preprint arXiv:1308.4805},
  year   = {2015}
}

Comments

10 pages, 9 figures

R2 v1 2026-06-22T01:13:16.586Z