Excitation of unidirectional exchange spin waves by a nanoscale magnetic grating

Abstract

Unidirectional propagation of spin waves is key to the realization of magnonic logic devices. Here, the authors experimentally demonstrate excitations of unidirectional exchange spin waves by a nanoscale magnetic grating fabricated on an ultrathin yttrium iron garnet film. The authors explain and model the nearly perfect unidirectional excitation by the chirality of the magnetodipolar interactions. Reversal of the magnetic configurations changes the direction of the exchange spin waves. Such results raise the prospect of a chiral magnonic logic without the need for fragile surface states.