Nonlinear Properties of Magnonic and Magnonic-Phononic Crystals
Y.Gulyaev, Yu.I.Bespyatykh, I.E.Dikshtein, S.A.Nikitov (Institute of Radioengineering & Electronics RAS, Moscow, Russia)
In a current work a new class of magnetic materials is described and analyzed. Drawing an analogy with photonic crystals possessing a photonic band, namely the frequency range where the wave propagation is forbidden, such magnetic media can be named magnonic and magnonic-phononic crystals. Such crystals represent the medium in which the magnetic (and/or elastic) properties are varied periodically. The simplest type of the one-dimensional magnonic crystals is a multilayered periodic structure composed from the layers with the different magnetization. Spin waves propagation through this structure is prohibited within the restricted bands. It is shown that a localized spin wave mode can exist in a forbidden zone if the periodicity of the system is broken in a particular place. Such magnonic crystals in a microwave frequency range can be a challenge for photonic crystals operating at the visual light frequency band. This work represents the analysis of such systems along with theoretical and numerical calculations of forbidden zones and spin wave modes. Nonlinear properties of such crystals are investigated and novel nonlinear effects due to interaction between spin and acoustic waves in such complex systems are discussed. Bistability and soliton formation and interaction are some examples of these nonlinear effects.
Section : 2