Nonreciprocal Surface Acoustic Waves in Multilayers with Magnetoelastic and Interfacial Dzyaloshinskii-Moriya Interactions

The design of modern circulators and isolators relies on nonreciprocal (discriminating forward and backward wave vectors, breaking time-reversal symmetry) electromagnetic waves in magnetic materials. Creating such devices that are small enough for portable electronics (think mobile phones) remains challenging. The authors show theoretically the nonreciprocal propagation of surface acoustic waves in multilayers with simultaneous magnetoelastic and Dzyaloshinskii-Moriya interactions. Despite both interactions being relatively weak, their interplay creates up to 45 dB of isolation for counterpropagating waves, making these multilayers promising for miniaturized rf isolators.