The emergence of various topological semimetal states presents a novel opportunity for enhancing the efficiency of thermoelectric transport. This study introduces a recipe to improve the thermoelectric (TE) performance in topological materials containing single-pair Weyl points (SP WPs) fermions and phonons. The recipe focuses on two key factors contributing to the enhancement of TE performance: the increase in the density of states to achieve a high power factor, and the introduction of additional phonon scattering to reduce the lattice thermal conductivity. The proposed recipe is confirmed in a half-metallic SP WPs material BaNiIO₆ through first-principles methods. An enhanced density of states arises near the energy of the SP WPs in BaNiIO₆, leading to a peak power factor connected to the complex Fermi surface due to the degeneracy of Weyl pockets in energy. Furthermore, it is shown that the SP WPs phonons in BaNiIO₆ possess a high scattering rate and can likely contribute to the low lattice thermal conductivity, especially when two crossing points in SP WPs do not degenerate in frequency. The new recipe can be used for discovering high-performance thermoelectric materials in the future by utilizing the transport advantages of degenerate-in-energy SP WPs fermions and non-degenerate-in-frequency SP WPs phonons.

中文翻译：

---

增强携带单对韦尔点费米子和声子的拓扑材料热电性能的新方法

各种拓扑半金属态的出现为提高热电传输效率提供了新的机会。本研究介绍了一种提高含有单对外尔点 (SP WP) 费米子和声子的拓扑材料热电 (TE) 性能的方法。该方案重点关注有助于增强 TE 性能的两个关键因素：增加态密度以实现高功率因数，以及引入额外的声子散射以降低晶格热导率。通过第一原理方法，所提出的配方在半金属 SP WPs 材料 BaNiIO _{6中得到了证实。 BaNiIO 6}中 SP WP 的能量附近出现增强的态密度，由于 Weyl 口袋能量的简并，导致与复杂费米表面相关的峰值功率因数。此外，研究表明BaNiIO ₆中的SP WP声子具有高散射率，并且可能有助于降低晶格热导率，特别是当SP WP中的两个交叉点频率不简并时。新配方可用于利用简并能量SP WPs费米子和非简并频率SP WPs声子的输运优势，在未来发现高性能热电材料。