High-Efficiency Elastic Wave Rectifier in One-Dimensional Linear Magnetoelastic Phononic Crystal Slabs by an External Magnetostatic Field

Reciprocity is a fundamental property of wave propagation in linear time-invariant media. However, it is substantially harder to break reciprocity for elastic waves in a linear elastic system with the help of a magnetostatic field, since elastic waves are spinless in nature. Here, we realize nonreciprocal elastic waves in one-dimensional linear magnetoelastic phononic crystal slabs by an external magnetostatic field. The asymmetric dispersion of spin waves, which is induced by the simultaneous breaking of the time-reversal and spatial-inversion symmetries, results in an efficient elastic wave diode effect in a periodic system due to magnetoelastic interactions. Remarkably, a bidirectional nonreciprocity of elastic waves is achieved based on the folding-back effect of the periodic structure. Our proposed scheme opens up avenues for the design of nonreciprocal devices, such as on-chip tunable diodes, rectifiers, and topological insulators.