Nutation Spectroscopy of a Nanomagnet Driven into Deeply Nonlinear Ferromagnetic Resonance

• DOI: 10.1103/physrevx.9.041036
• Publication Date: 2019-11-19T14:08:42Z
• Authors: Y. Li; V. V. Naletov; O. Klein; J. L. Prieto; M. Muñoz; V. Cros; P. Bortolotti; A. Anane; C. Serpico; G. de Loubens
• Keywords: Nanomagnet; Precession; Nutation; Magnetization dynamics; Spin wave; Larmor precession

Strongly out-of-equilibrium regimes in magnetic nanostructures exhibit novel properties, linked to the nonlinear nature of magnetization dynamics, which are great fundamental and practical interest. Here, we demonstrate that ferromagnetic resonance driven by microwave fields can occur with substantial spatial coherency at an unprecedented large angle precessions, is normally prevented onset spin-wave instabilities turbulent dynamics. Our results show this limitation be overcome nanomagnets, where geometric confinement drastically reduces density modes. When obtained deeply regime perturbed, undergoes eigenoscillations around steady state due torques tending restore stable large-angle periodic trajectory. These substantially different from usual modes ground because their existence connected presence a coherent precession. They experimentally investigated new spectroscopic technique based on application second excitation field tuned resonantly drive them. This two-tone spectroscopy enables us they consist slow nutations precession, whose frequencies set balance restoring torques. experimental findings well accounted for analytical model derived systems uniaxial symmetry. also provide means controlling highly dynamics nanostructures, opening interesting applicative opportunities context nanotechnologies.Received 9 April 2019Revised 4 September 2019DOI:https://doi.org/10.1103/PhysRevX.9.041036Published American Physical Society under terms Creative Commons Attribution 4.0 International license. Further distribution work must maintain attribution author(s) published article's title, journal citation, DOI.Published SocietyPhysics Subject Headings (PhySH)Research AreasMagnetization dynamicsCondensed Matter, Materials & Applied Physics