标题： 晶体材料中双热输运通道的协同抑制策略 显示英文标题

标题： Cooperative Suppression Strategy for Dual Thermal Transport Channels in Crystalline Materials

摘要： 我们提出了一种新的设计原理，通过“重-轻和软-硬”结构基元，在晶体材料中实现超低热导率。 通过将重原子和轻原子种类与软键合和硬键合网络结合，粒子-like（$\kappa_p$）和波-like（$\kappa_c$）声子输运通道同时被抑制。 第一性原理计算表明，这种结构诱导出分层的声子谱：软键合的重原子产生密集的低频模，增强散射并降低$\kappa_p$，而硬键合的轻原子产生稀疏的高频光学分支，破坏相干性并降低$\kappa_c$。 高通量筛选识别出 Tl$_4$SiS$_4$ ($\kappa_p$ = 0.10, $\kappa_c$ = 0.06 W/mK) 和 Tl$_4$GeS$_4$ ($\kappa_p$ = 0.09, $\kappa_c$ = 0.06 W/mK) 作为具有在两个通道中强烈抑制传输的代表性候选材料。 一个最小的1D三原子链模型进一步证明了该机制的普遍性，提供了一种超越传统$\kappa_p$-$\kappa_c$限制的声子工程新范式。 显示英文摘要

摘要： We propose a novel design principle for achieving ultralow thermal conductivity in crystalline materials via a "heavy-light and soft-stiff" structural motif. By combining heavy and light atomic species with soft and stiff bonding networks, both particle-like ($\kappa_p$) and wave-like ($\kappa_c$) phonon transport channels are concurrently suppressed. First-principles calculations show that this architecture induces a hierarchical phonon spectrum: soft-bonded heavy atoms generate dense low-frequency modes that enhance scattering and reduce $\kappa_p$, while stiff-bonded light atoms produce sparse high-frequency optical branches that disrupt coherence and lower $\kappa_c$. High-throughput screening identifies Tl$_4$SiS$_4$ ($\kappa_p$ = 0.10, $\kappa_c$ = 0.06 W/mK) and Tl$_4$GeS$_4$ ($\kappa_p$ = 0.09, $\kappa_c$ = 0.06 W/mK) as representative candidates with strongly suppressed transport in both channels. A minimal 1D triatomic chain model further demonstrates the generality of this mechanism, offering a new paradigm for phonon engineering beyond the conventional $\kappa_p$-$\kappa_c$ trade-off.