Modulation of magnonic bands of dipole-exchange spin waves in fishbone-like yttrium iron garnet nanostrip magnonic crystal waveguides

Abstract

We designed a fishbone-like yttrium iron garnet nanostrip magnonic crystal waveguide structure and investigated the modulation of the structural parameters to the propagating characteristics of dipole-exchange spin waves by using the object oriented micromagnetic framework numerical calculation method. The number, position, and width of the allowed bands in the magnonic band maps can be manipulated by changing the tilted angles of the sides branch (θ), the width of the ‘main bone’ (W1), and the separatiion distance between the two side branches (P2). Besides the normal band gaps appearing at the Brillouin zone (BZ) boundaries, extra band gaps emerge at certain values of k in the dispersion curves with a deviation Λ away from the BZ boundaries which can also be controlled by θ, W1, and P2. Compared with other parameters, the tilted angle θ has a greater impact on spin wave propagation.