Highly Nonreciprocal Spin Waves Excited by Magnetoelastic Coupling in a<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mi>Ni</mml:mi></mml:math>/<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mi>Si</mml:mi></mml:math>Bilayer

Abstract

We demonstrate a largely enhanced nonreciprocal propagation of spin waves (SWs) magnetoelastically excited in $\mathrm{Ni}$/$\mathrm{Si}$ bilayer films. The nonreciprocity is attributed to the shear component of the strain tensor, which can be enlarged by increasing the thickness of the $\mathrm{Si}$ layer. By evaporating a 400-nm-thick $\mathrm{Si}$ layer on a $\mathrm{Ni}$ film, we enhanced the nonreciprocal ratio by up to 1200%. This finding paves the way for rectification of SWs in magnonic devices.

Topics & Concepts