基于声子的Weyl半金属TaAs弹性系数测定
Phonon-based determination of elastic coefficients in the Weyl semimetal TaAs
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中文总结 AI 辅助
本研究结合第一性原理声子计算与弹性连续介质模型，高效测定Weyl半金属TaAs的弹性系数，结果与文献吻合，可替代传统应变法并有望关联实验表征。
中文摘要 AI 辅助
可靠测定拓扑半金属的弹性质对理解应变相关效应至关重要，但常受限于方法学和计算方面的限制。本研究将第一性原理声子计算与弹性连续介质模型相结合，以测定Weyl半金属TaAs的弹性质。从声学声子分支提取的声速被用于获取全套弹性模量，这些模量与文献中先前报道的数值吻合良好。基于这些结果，我们推导了标准弹性参数，如体模量、剪切模量、杨氏模量和泊松比。该方法凸显了一种计算效率高的替代方案，可替代传统的基于应变的方法，避免了施加剪切应变时需要使用大超胞的问题，从而避免了电子基组可能出现的应变诱导不一致性，同时为与Weyl半金属晶格动力学的实验表征（如拉曼或布里渊-曼德尔施塔姆散射）建立联系提供了可能。
英文摘要
Reliable determination of elastic properties in topological semimetals is essential for understanding strain-related effects, but is often hindered by methodological and computational limitations. In this work, we combine first-principles phonon calculations with an elastic continuum model to determine the elastic properties of Weyl semimetal TaAs. The sound velocities extracted from the acoustic phonon branches are used to obtain the full set of elastic moduli, which show good agreement with previously reported values in the literature. From these results, we derive standard elastic parameters such as bulk, shear, and Young's moduli, and the Poisson ratio. This approach highlights a computationally efficient alternative to conventional strain-based methods, avoiding the need for large supercells when shear is applied, and thus possible strain-induced inconsistencies in the electronic basis, while providing a possibility to connect with experimental characterizations (e.g. Raman or Brillouin-Mandelstam scattering) of the lattice dynamics in Weyl semimetals.
