标题： 单层铍烯中不寻常的声子热输运机制 显示英文标题

标题： Unusual Phonon Thermal Transport Mechanisms in Monolayer Beryllene

摘要： 我们使用线性化声子玻尔兹曼输运方程计算单层铍烯的热导率，其中原子间力常数来源于\textit{从头计算}计算。 单层铍烯在室温下表现出令人印象深刻的热导率为 270 W/m$\cdot$K，超过块体铍的 100% 以上。 我们的研究揭示了显著的温度依赖行为：在低温下为$\kappa \sim T^{-2}$，归因于更高的正常声子-声子散射，而在高温下为$\kappa \sim T^{-1}$，这是由于 Umklapp 声子相互作用。 模式特异性分析表明，寿命较长的弯曲声子是热导率的主要贡献者，占约 80%。 这种主导地位是由于它们在垂直方向上的散射率较低，这是由于散射过程的相空间受限。 此外，我们的研究结果强调了抑制的 Umklapp 散射和弯曲模式的相空间减少，为单层铍烯中易于热导率的理解及其在先进热管理应用中的潜力提供了全面的认识。 显示英文摘要

摘要： We compute the thermal conductivity of monolayer beryllene using the linearized phonon Boltzmann transport equation with interatomic force constants obtained from \textit{ab-initio} calculations. Monolayer beryllene exhibits an impressive thermal conductivity of 270 W/m$\cdot$K at room temperature, exceeding that of bulk beryllium by over 100%. Our study reveals a remarkable temperature-dependent behavior: $\kappa \sim T^{-2}$ at low temperatures, attributed to higher normal phonon-phonon scatterings, and $\kappa \sim T^{-1}$ at high temperatures, due to Umklapp phonon interactions. Mode-specific analysis reveals that flexural phonons with longer lifetimes are the primary contributors to thermal conductivity, accounting for approximately 80%. This dominance results from their lower scattering rates in the out-of-plane direction due to a restricted phase space for scattering processes. Additionally, our findings highlight suppressed Umklapp scattering and reduced phase space for flexural modes, providing a thorough understanding of the eased thermal conductivity in monolayer beryllene and its potential for advanced thermal management applications.