Ultra-narrow spin wave metasurface for focusing application

Abstract

In this paper, we show that the phase shift of the spin waves can be controlled by metasurface formed by an ultra-narrow non-magnetic spacer separating two thin ferromagnetic films. For this purpose, we exploit the strength of the exchange coupling of RKKY type between the films which allows to tune the phase of the transmitted spin waves in the wide range of angles [−π/2;π/2]. We combined the phase-shift dependency along the interface with the lens equation to demonstrate numerically the metalens for spin waves.