Theory of semi-conducting moiré materials

半导体莫尔材料理论

• 批准号: 428802713
• 负责人: Professorin Dr. Sangeeta Sharma, Ph.D.
• 金额: --
• 依托单位: Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (MBI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/428802713?language=en
• 关键词: Theory; semi; conducting; moir; materials

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.

原子薄的二维晶体堆叠成多层，给凝聚态物质界引入了一个本质上的新系统：小角云纹晶格。石墨烯以外的云纹系统是这种材料的原型，受到制造技术发展的推动，现在开始研究。石墨烯云纹的非凡物理特性使人们希望，一般的云纹材料，特别是由二维半导体制成的云纹材料，可能会呈现出一种既具有基础科学兴趣，又具有潜在广泛技术应用的系统。然而，由二维半导体（如过渡金属二硫族化物）产生的小角度云纹的结构复杂性，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云纹的基本电子结构的理解：(i)连续统理论的发展和应用，将允许探索小角度极限，（ii）间隙边缘的性质和云纹驱动局域化在小角度极限中的作用，以及（iii）“云纹设计”小层半导体间隙边缘的可能性。在积累了这些专业知识之后，我们计划研究这种系统的关键光学特性。特别地，光学吸收光谱将用无参数的“自举”方法计算，并研究单粒子和激子局部化在云纹上的相互作用。