２次元物質ゲルマネンの実デバイス環境下における電子状態・輸送特性の理論研究

石墨烯的缺点刺激科学家研究石墨烯以外的新型2D材料。锗烷烯和锡烯具有各种迷人的性质，如Dirac-cone，载流子迁移率和量子自旋霍尔效应（QSHE）。虽然在实验中已经在几种底物上合成了它们，但仍然缺乏合适的底物来保持有吸引力的Dirac-cone和QSHE。通过密度泛函理论与材料信息学相结合，我们从数据库中185，000多个条目中找到了几种适合锗烯和锡烯的底物。模型分析表明，衬底与靶二维材料之间的相互作用等效于赝电场。（Physical Review B，96，075427）此外，我们正在实施一种机器学习方法，以提供对2D材料沉积过程的准确和快速的模拟。除了最初的计划，我们还将目光投向了过渡金属二硫属化物（TMD）家族的成员WTe 2。由于其奇异的非饱和磁电阻效应和可能的II型外尔锥，它已成为二维材料中一颗冉冉升起的星星。然而，对WTe 2的表面弛豫和表面电子结构的研究还很不够，特别是对少层板的研究。为了解决这些问题，我们研究了精确的表面弛豫和机械可调的电子结构在几层WTe 2（应用物理快报，10，045702; ACS纳米，11，11459）。在少层WTe 2中发现的机械可调表面偶极子的研究正在准备中。

The drawbacks of graphene stimulate scientists to investigate novel 2D materials beyond graphene. Germanene and stanene have various fascinating properties, such as the Dirac-cone, ultrahigh carrier mobility, and the quantum spin Hall effect (QSHE). While they have been synthesized on several substrates in experiment, there is still a lack of suitable substrates to preserve the attractive Dirac-cone and QSHE. By combining DFT with materials informatics, we have found several suitable substrates for germanene and stanene from more than 185, 000 entries in the database. The interaction between the substrate and the target 2D materials is equivalent to pseudoelectric field, as revealed by our model analysis. (Physical Review B, 96, 075427) Furthermore, we are implementing a machine learning approach to provide accurate and fast simulation of the deposition procedure of 2D materials.In addition to the original plan, we also put our eyes on WTe2, a member of transition metal dichalcogenides (TMDs) family. It has been a rising star in 2D materials due to the exotic non-saturating magnetoresistance (MR) and the possible type-II Weyl cone. However, the study about the surface relaxation and surface electronic structure is insufficient in WTe2, especially for few layer slabs. To solve the problems, we have investigated the accurate surface relaxation and mechanically tunable electronic structure in few-layer WTe2 (Applied Physics Express, 10, 045702; ACS Nano, 11, 11459). The research about the mechanically tunable surface dipole found in few-layer WTe2 is in preparation.