Theory of semi-conducting moiré materials

将原子级薄的二维晶体堆叠成多层，为凝聚态物质社区引入了一个本质上新的系统：小角度莫尔晶格。在制造技术发展的推动下，超越石墨烯的莫尔系统，这种材料的原型，现在开始被研究。 石墨烯莫尔条纹的非凡物理学带来了希望，即一般的莫尔条纹材料，特别是当由2d半导体创建时，可能会呈现出一种既具有基本科学兴趣又具有潜在广泛技术应用的系统。然而，从二维半导体（如过渡金属二硫属化物）产生的小角度莫尔结构的复杂性，迄今为止，阻碍了对这些系统的探索。因此，我们的目标是提供对小角度半导体莫尔的基本电子结构的理解：（i）发展和应用连续统理论，以便探讨小角度极限，（ii）间隙差距边缘的性质和莫尔条纹驱动的局部化在小角度极限中的作用，以及（iii）“莫尔条纹设计”少层半导体的差距边缘的可能性。 在积累了这些专业知识之后，我们计划研究这些系统的关键光学特性。特别是光学吸收光谱将计算与参数自由的“自举”的方法，和相互作用的单粒子和激子本地化的云纹调查。

The stacking of atomically thin 2D crystals into multilayers has introduced to the condensed matter community an essentially new system: the small angle moire lattice. Moire systems beyond graphene, the prototype of such materials, are, spurred by developments in fabrication techniques, now beginning to be investigated. The remarkable physics of the graphene moire leads to hopes that the general moire material, especially when created from 2d semiconductors, may present a system both fundamental scientific interest, as well as being of potentially wide technological application. However, the structural complexity of small angle moires created from 2d semiconductors such as transition metal dichalcogenides, has, to date, prevented exploration these systems.We thus aim to provide an understanding of the basic electronic structure of small angle semi-conducting moire: (i) the development and application of continuum theories that will allow the small angle limit to be explored, (ii) the nature of the gap edge and the role of moire driven localization in the small angle limit, and (iii) the possibility of “moire designing” the gap edge of few layer semiconductors. Subsequent to the accumulation of this expertise we then plan to investigate the key optical properties of such systems. In particular the optical absorption spectrum will be calculated both with a parameter free "bootstrap" approach, and the interplay of single particle and excitonic localization on the moire investigated.