论文标题
石墨烯和过渡金属二分法的扭曲双层中的二型二十二体学
Twistronics versus straintronics in twisted bilayers of graphene and transition metal dichalcogenides
论文作者
论文摘要
几项数值研究表明，石墨烯（TBLG）和过渡金属二核苷（TMDS）的扭曲双层的电子性能可通过堆叠层的应变工程来调整。特别是，发现刚性和松弛的TBLG的低能莫伊尔带的平坦度基本上对菌株很敏感。但是，据我们所知，尚无对应变对此类频段的影响的完整分析计算。我们基于Moiré平面带的连续模型，该模型是石墨烯扭曲同型同型同型同型同型的低能汉密尔顿和在小扭曲角度的应变下。我们获得了应变符号的狄拉克速度的分析表达式，并解释了应变在平坦带出现中的作用。我们讨论应变如何纠正扭曲角度，并使它们更接近魔法角度$θ_m\ sim1.05^{\ circ} $的TBLG及其如何减少以TMDS扭曲同金的电荷中立性最低能量频段的宽度。将分析结果与数值和实验性发现以及基于连续模型的数值计算进行了比较。
Several numerical studies have shown that the electronic properties of twisted bilayers of graphene (TBLG) and transition metal dichalcogenides (TMDs) are tunable by strain engineering of the stacking layers. In particular, the flatness of the low-energy moiré bands of the rigid and the relaxed TBLG was found to be, substantially, sensitive to the strain. However, to the best of our knowledge, there are no full analytical calculations of the effect of strain on such bands. We derive, based on the continuum model of moiré flat bands, the low-energy Hamiltonian of twisted homobilayers of graphene and TMDs under strain at small twist angles. We obtain the analytical expressions of the strain-renormalized Dirac velocities and explain the role of strain in the emergence of the flat bands. We discuss how strain could correct the twist angles and bring them closer to the magic angle $θ_m\sim1.05^{\circ}$ of TBLG and how it may reduce the widths of the lowest-energy bands at charge neutrality of the twisted homobilayer of TMDs. The analytical results are compared with numerical and experimental findings and also with our numerical calculations based on the continuum model.
