We study heat transport across individual grain boundaries in suspended monolayer graphene using extensive classical molecular dynamics (MD) simulations. We construct bicrystalline graphene samples containing grain boundaries with symmetric tilt angles using the two-dimensional phase field crystal method and then relax the samples with MD. The corresponding Kapitza resistances are then computed using nonequilibrium MD simulations. We find that the Kapitza resistance depends strongly on the tilt angle and shows a clear correlation with the average density of defects in a given grain boundary, but is not strongly correlated with the grain boundary line tension. We also show that quantum effects are significant in quantitative determination of the Kapitza resistance by applying the mode-by-mode quantum correction to the classical MD data. The corrected data are in good agreement with quantum mechanical Landauer-Butticker calculations.

中文翻译：

---

跨越石墨烯中单个晶界的 Kapitza 热阻

我们使用广泛的经典分子动力学 (MD) 模拟研究悬浮单层石墨烯中跨单个晶界的热传输。我们使用二维相场晶体方法构建包含具有对称倾斜角的晶界的双晶石墨烯样品，然后用 MD 松弛样品。然后使用非平衡 MD 模拟计算相应的 Kapitza 电阻。我们发现 Kapitza 电阻强烈依赖于倾斜角，并且与给定晶界中的平均缺陷密度有明显的相关性，但与晶界线张力没有很强的相关性。我们还表明，通过将逐模式量子校正应用于经典 MD 数据，量子效应在 Kapitza 电阻的定量测定中具有重要意义。