In this work, we report a mechanism of stop-band formation in a multilayer array of germanium nanoparticles embedded in a crystalline silicon matrix. When only a single layer of nanoparticles is embedded, the local resonance, induced by the destructive interference between two different phonon wave paths, gives rise to several sharp and significant transmittance dips. On the other hand, when the number of the layers of embedded nanoparticles further increases to ten, a stop band with complete phonon reflection is formed due to the two-path resonance Bragg-type phonon interference. The wave packet simulations further uncover that the stop band originates from the collective phonon resonances in the embedded nanoparticles layers. Compared with the traditional stop-band formation mechanism that is the single-path Bragg reflection, the two-path phonon-interference resonance mechanism has a significant advantage in not requiring the strict periodicity in the embedded nanoparticles multilayer array. We also demonstrate that the stop band can significantly suppress thermal conductance in the low-frequency regime. Our work provides a robust, scalable, and easily modulable stop-band formation mechanism, which opens a degree of freedom for phononics-related heat control.

中文翻译：

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两径声子干扰共振在具有嵌入式纳米颗粒多层阵列的硅晶体基质中诱导阻带

在这项工作中，我们报告了嵌入晶体硅基质中的锗纳米颗粒多层阵列中阻带形成的机制。当仅嵌入纳米颗粒的单层时，由两个不同声子波路径之间的相消干涉引起的局部共振会导致几次陡峭而显着的透射率下降。另一方面，当嵌入的纳米颗粒的层数进一步增加到十时，由于两路径共振布拉格型声子干涉而形成具有完全的声子反射的阻带。波包模拟进一步揭示了阻带源自嵌入的纳米颗粒层中的集体声子共振。与传统的阻带形成机制（单路径布拉格反射）相比，在不要求嵌入式纳米颗粒多层阵列中具有严格的周期性的情况下，两径声子干扰共振机制具有显着的优势。我们还证明，阻带可以显着抑制低频状态下的热导。我们的工作提供了一种健壮，可扩展且易于调制的阻带形成机制，从而为与声子相关的热控制打开了自由度。