Abstract There are growing efforts to control thermal transport via coherent phonons in one-dimensional superlattices. Typically, the difference in intrinsic lattice structures of the constituent materials generates an interface disorder during the fabrication process, limiting the coherent phonon transport manipulation. On the other hand, flexible integration and atomistic interlayer smoothness of a van der Waals (vdW) heterostructure provide an ideal platform for coherent phonon transport manipulations. Toward the ultimate goal of designing small thermal-conductivity materials at room temperature, herein we investigate the controllability of coherent phonon transport in vdW graphene-MoS2 heterostructures with different stacking orders using non-equilibrium molecular dynamics simulations. Using Bayesian optimization–based materials informatics, the optimal stacking order of graphene and MoS2 is efficiently identified from tens of thousands of candidates with varying degrees of phonon localization. The obtained thermal conductivity of the optimized heterostructure (0.026 W/m-K) is significantly lower than that of its building blocks (pristine MoS2 and graphene). Additionally, the optimized heterostructure has a thermal conductivity lower than those of representative low thermal conductivity solid materials (amorphous oxide and disordered crystalline oxides), which usually range between 1.3 and 3 W/m-K at room temperature, and the amorphous polymers, which is on the order of 0.1 W/m-K. The underlying physical mechanism of coherent phonon localization is uncovered by calculating the phonon transmission in the optimum heterostructure and analyzing the histogram distribution pattern of the phonon transmissions in different disordered stacking heterostructures. The presence of localization is further validated by a comparative study of the optimum heterostructure to pristine graphene with introduced defects, changed the thickness and temperature of the system. Our work provides insight into the coherent phonons transport behavior in the atomistically smooth vdW structure, which is essential for further development of phononics.

中文翻译：

---

范德华石墨烯-二硫化钼异质结构中相干热传导的极限阻抗

摘要 通过一维超晶格中的相干声子来控制热传输的努力越来越多。通常，组成材料的内在晶格结构的差异在制造过程中产生界面无序，限制了相干声子传输操作。另一方面，范德华（vdW）异质结构的灵活集成和原子层间平滑性为相干声子传输操作提供了理想的平台。为了在室温下设计小型导热材料的最终目标，我们在本文中使用非平衡分子动力学模拟研究了具有不同堆叠顺序的 vdW 石墨烯-MoS2 异质结构中相干声子传输的可控性。使用基于贝叶斯优化的材料信息学，石墨烯和二硫化钼的最佳堆叠顺序可以从数万个具有不同声子定位程度的候选物中有效识别。优化后的异质结构获得的热导率 (0.026 W/mK) 显着低于其构建块（原始 MoS2 和石墨烯）的热导率。此外，优化的异质结构的热导率低于典型的低热导率固体材料（无定形氧化物和无序结晶氧化物），室温下通常在 1.3 到 3 W/mK 之间，而无定形聚合物则在0.1 W/mK 的数量级。通过计算最佳异质结构中的声子传输并分析不同无序堆叠异质结构中声子传输的直方图分布模式，揭示了相干声子定位的潜在物理机制。通过对引入缺陷的原始石墨烯的最佳异质结构进行比较研究，进一步验证了局部化的存在，从而改变了系统的厚度和温度。我们的工作提供了对原子平滑 vdW 结构中相干声子传输行为的洞察，这对于声子学的进一步发展至关重要。通过对引入缺陷的原始石墨烯的最佳异质结构进行比较研究，进一步验证了局部化的存在，从而改变了系统的厚度和温度。我们的工作提供了对原子平滑 vdW 结构中相干声子传输行为的洞察，这对于声子学的进一步发展至关重要。通过对引入缺陷的原始石墨烯的最佳异质结构进行比较研究，进一步验证了局部化的存在，从而改变了系统的厚度和温度。我们的工作提供了对原子平滑 vdW 结构中相干声子传输行为的洞察，这对于声子学的进一步发展至关重要。