Disorder limits the coherent phonon transport in two-dimensional phononic crystal structures
Disorder limits the coherent phonon transport in two-dimensional phononic crystal structures
复制标题
DOI：
10.1039/c9nr02548k
复制
发表时间：
2019-06-28
期刊：
影响因子：
6.7
通讯作者：
Chen, Jie
中科院分区：
文献类型：
--
作者：
Hu, Shiqian;Zhang, Zhongwei;Chen, Jie
近年来，在周期性声子结构中通过相干声子控制热输运的研究越来越多；然而，在环境温度下直接观测相干声子输运在实验上是非常困难的，并且相干声子对总热导率的重要性迄今尚未得到严格的评估。本研究采用非平衡分子动力学模拟方法，研究了室温下C3N声子晶体（CNPnC）结构中通过改变孔隙率的相干声子输运。将孔随机分布，构建无序C3N （D-C3N）结构，通过声子透射系数、声子波包模拟、声子参与比和空间能量密度揭示相干声子的局域化，导致导热系数显著降低。最后讨论了长度、温度和应变对CNPnC和D-C3N导热系数的影响。我们的研究为相干声子的输运行为提供了一个坚实的认识，这将有助于基于相干声子的声子相关控制。
Recently, increasing efforts are being made to control thermal transport via coherent phonons in periodic phononic structures; however, the direct observation of coherent phonon transport is experimentally very difficult at ambient temperature, and the importance of coherent phonons to the total thermal conductivity has not been critically assessed to date. In this study, using the non-equilibrium molecular dynamics simulations, we studied coherent phonon transport in a C3N phononic crystal (CNPnC) structure at room temperature by changing the porosity. When the holes were randomly distributed to construct the disordered C3N (D-C3N) structure, the localization of the coherent phonons was revealed by the phonon transmission coefficient, phonon wave packet simulation, phonon participation ratio and spatial energy density, which led to a significant reduction in the thermal conductivity. Finally, the effects of the length, temperature and strain on the thermal conductivity of CNPnC and D-C3N have also been discussed. Our study provides a solid understanding of the coherent phonon transport behavior, which will be beneficial for phononic-related control based on coherent phonons.