Open AccessLarge Hysteresis effect in Synchronization of Nanocontact Vortex Oscillators by Microwave Fields
Author(s) -
Salvatore Perna,
L. López-Dı́az,
M. d’Aquino,
C. Serpico
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep31630
Subject(s) - vortex , physics , hysteresis , condensed matter physics , synchronization (alternating current) , oscillation (cell signaling) , asymmetry , micromagnetics , amplitude , nonlinear system , field (mathematics) , phase diagram , magnetic field , microwave , phase (matter) , mechanics , magnetization , topology (electrical circuits) , quantum mechanics , mathematics , combinatorics , biology , pure mathematics , genetics
Current-induced vortex oscillations in an extended thin-film with point-contact geometry are considered. The synchronization of these oscillations with a microwave external magnetic field is investigated by a reduced order model that takes into account the dynamical effects associated with the significant deformation of the vortex structure produced by the current, which cannot be taken care of by using the standard rigid vortex theory. The complete phase diagram of the vortex oscillation dynamics is derived and it is shown that strong hysteretic behavior occurs in the synchronization with the external field. The complex nonlinear nature of the synchronization manifests itself also through the appearance of asymmetry in the locking frequency bands for moderate microwave field amplitudes. Predictions from the reduced order model are confirmed by full micromagnetic simulations.