Anisotropic spin-wave propagation in asymmetric width modulated Ni80Fe20 nanostripes

Nanoscale magnonic waveguides have attracted significant attention due to their potential applications in on-chip GHz frequency signal communication and processing. Here, we report a strongly anisotropic magnonic band structure and band gap in an asymmetric sawtooth shaped width modulated Ni80Fe20 nanostripe array using Brillouin light scattering spectroscopy. The experimental observation is reproduced numerically by using plane-wave method. Further, micromagnetic simulations underpin that the shape anisotropy of the nanostripe and the continuous variation of spin configuration with bias magnetic field orientation play crucial roles in steering the anisotropic spin-wave propagation in this structure. Based on the observed spin-wave anisotropy, we numerically propose frequency dependent XNOR and XOR logic gates intended for integrated spin-based nanocircuits.