Two-path phonon interference resonance induces a stop band in a silicon crystal matrix with a multilayer array of embedded nanoparticles
Two-path phonon interference resonance induces a stop band in a silicon crystal matrix with a multilayer array of embedded nanoparticles
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DOI：
10.1103/physrevb.102.024301
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发表时间：
2020-01
影响因子：
3.7
通讯作者：
Shiqian Hu;Lei Feng;Cheng Shao;I. Strelnikov;Y. Kosevich;J. Shiomi
中科院分区：
文献类型：
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作者：
Shiqian Hu;Lei Feng;Cheng Shao;I. Strelnikov;Y. Kosevich;J. Shiomi
在这项工作中，我们报告了嵌入在晶体硅基质中的多层锗纳米颗粒阵列中形成阻带的机制。当只嵌入一层纳米粒子时，由于两个不同声子波路径之间的相消干涉而引起的局部共振导致了几个明显的透过率急剧下降。另一方面，当纳米粒子的嵌入层数进一步增加到10层时，由于双路径共振布拉格型声子干涉，形成了一个完全反射声子的阻带。波包模拟进一步揭示了阻带来源于嵌入的纳米粒子层中的集体声子共振。与传统的单程布拉格反射阻带形成机制相比，双程声子干涉共振机制在嵌入型纳米多层膜阵列中具有不要求严格的周期性的显著优势。我们还证明了在低频区，阻带能显著抑制热导。我们的工作提供了一个健壮的、可扩展的、易于调节的阻带形成机制，这为与声学相关的热控制打开了一个自由度。
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.