Magnonic Devices: Numerical Modelling and Micromagnetic Simulation Approach

Magnonics—the study of spin waves—has seen a remarkable scope for the creation of magnetic field-controlled devices with properties tailored on the nanoscale. It aims to control and manipulate spin waves in ferromagnetic material. Spin wave can effectively carry and process information in magnetic nanostructures. The most controllability of their functioning is by an external magnetic field. The magnonic devices which are periodically modulated in space are seen as very promising devices because of the possibility of tunning their band structure. Periodically modulated magnonic devices can also be called as “magnonic crystal” magnetic counter part of photonic crystal, with spin wave acting as information carrier. Magnonic crystals are better candidates for miniaturization, since the wavelength of spin wave is several orders of magnitude shorter than that of electromagnetic waves of the same frequency. An example of one-dimensional magnonic crystal is a multilayered magnetic structure consisting of alternated ferromagnetic layers. The basic advantage of a such device is that frequency position and width of the band gap are tunable by an applied field and through material properties. The dispersion properties can be tuned by changing the dimensions of magnonic waveguide. Spectrum of magnonic crystal shows band gaps in which spin wave cannot propagate. Such band gaps have been experimentally studied using Brillouin light scattering spectroscopy [1, 2] and time-resolved scanning Kerr microscopy [3]. The study of magnonic crystal is first proposed in [4]. Puszkarski and Krawczyk have theoretically calculated the magnonic band structure of 2D MCs consisting of infinitely long cylindrical Fe rods periodically embedded in a yttrium iron garnet (YIG) background [5]. The materials Fe and YIG were selected for their large difference in magnetic properties, as it has been predicted that the larger the difference, the wider would be the band gap width. They investigated the…