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.

中文翻译：

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一维线性静磁弹性声子晶体平板中的高效静波整流器

互易性是波在线性时不变介质中传播的基本属性。然而，由于弹性波本质上是无旋转的，因此在静磁场的帮助下打破弹性波在线性弹性系统中的互易性实际上更加困难。在这里，我们通过外部静磁场在一维线性磁弹性声子晶体平板中实现不可逆的弹性波。由于时间弹性和空间反转对称性的同时破坏而引起的自旋波的非对称色散，由于磁弹性相互作用而在周期系统中产生有效的弹性波二极管效应。值得注意的是，基于周期性结构的折回效应，实现了弹性波的双向不可逆性。