AI 中文总结
研究通过非平衡分子动力学模拟铜-石墨烯-铜界面热传输，发现卡皮查电阻对晶格初始化等域配置敏感，两种初始化策略下电阻有两倍差异，且与传统预期不同，还指出铜晶格电导率有域尺寸和温度依赖性。
AI 中文摘要
我们使用非平衡分子动力学（NEMD）研究铜-石墨烯-铜界面的热传输，重点关注有限域长度和域配置（包括晶格初始化及相关石墨烯褶皱）对预测热导率和卡皮查电阻的影响。文献中NEMD模拟确定了石墨烯-铜界面卡皮查电阻的趋势，但模拟结果和可靠性可能严重依赖文献中未充分探索的配置选择。我们发现卡皮查电阻对影响晶格常数和原子密度的域配置选择具有很强的敏感性。两种传统晶格初始化策略在卡皮查电阻上产生两倍的差异，尽管晶格参数仅相差百分之几。这种行为伴随着石墨烯和铜声子谱的应变相关位移以及较低应变下声子重叠增加。与传统预期相反，更大的声子模式重叠与更高的卡皮查电阻一致，表明仅光谱重叠无法捕捉界面传热动力学。我们认为在具有较低残余应变的晶格中，界面附近会形成阻尼边界层并增加热阻，这由更宽界面区域内局部结构无序和局部光谱展宽的增加所表明。除了与晶格常数相关的应变和密度效应外，本研究中卡皮查电阻对域长度或边界温度强制没有显著依赖性。相比之下，铜晶格电导率表现出明显的域尺寸和温度依赖性，与声子平均自由程限制一致并得到声子光谱分析的支持。
英文摘要
We study thermal transport across copper-graphene-copper interfaces using Non-Equilibrium Molecular Dynamics (NEMD), focusing on the influence of finite domain length and domain configuration, including lattice initialisation and associated graphene wrinkling, on the predicted thermal conductivity and Kapitza resistance. In the literature, NEMD simulations identified trends in the Kapitza resistance of graphene-copper interfaces. However, the simulation outcomes and reliability may depend heavily on configuration choices that are underexplored in the literature. We identify a strong sensitivity of the Kapitza resistance to domain configuration choices that affect the lattice constants and atomic density. We show that two conventional lattice initialisation strategies yield a factor of two difference in the Kapitza resistance, despite differences of only a few per cent in the lattice parameters. This behaviour is accompanied by strain-dependent shifts in the graphene and copper phonon spectra, and by increased phonon overlap at lower strain. Counter to conventional expectations, greater phonon-mode overlap coincides with higher Kapitza resistance, showing that spectral overlap alone cannot capture the interfacial heat-transfer dynamics. We suggest that in lattices initialised with lower residual strain, a damping boundary layer develops near the interface, and increases thermal resistance, as indicated by increased local structural disorder and local spectral broadening over a wider interfacial region. Beyond strain- and density-related effects associated with the lattice constants, Kapitza resistance shows no significant dependence on domain length or boundary temperature enforcement in this study. By contrast, the copper lattice conductivity exhibits clear domain-size and temperature dependence, consistent with phonon mean-free-path limitations and supported by phonon spectral analysis.
