Microscopic understanding of correlations in twisted van der Waals [hetero]structures

扭曲范德华[异质]结构中相关性的微观理解

• 批准号: 443273985
• 负责人: Professor Dr. Carsten Honerkamp
• 金额: --
• 依托单位: Institut für Theoretische Festkörperphysik C
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/443273985?language=en
• 关键词: Microscopic; understanding; correlations; twisted; van

One of the grand promises of van der Waals heterostructures, especially of the latest wave of twisted graphene systems, are novel phases of matter driven by electronic interactions. Correspondingly, the goal of this research project, placed in research area C of this SPP, is to enhance our knowledge about interaction effects in these systems in a two-fold approach. On the one hand, we want to explore the rich zoo of twisted van der Waals hetero-structures beyond the bi- and multi-layer graphene paradigm. This will be undertaken on the qualitative level of effective low-energy or few-band models obtained from density functional theory characterizations as input to unbiased methods for the study of electron-electron correlations. On the other hand, we extend our study to incorporate the entirety of the large moiré Brillouin zone, explicitly keeping a larger span of high-energy degrees of freedom in the description. This allows us to make predictions that cannot be found considering the bands near the Fermi level alone. This second approach, again fed with ab-initio input obtained by collaborating theory groups in this priority program, gives us a chance to develop quantitatively controlled results that are not potentially hampered by complicated strong-interaction effects that occur easily in studies restricted to the few lowest bands. Finally, we can also use this scheme for a controlled down-folding to effective few-band band models, including screening effects beyond the random phase approximation. The expected outcome of these studies includes phase diagrams for existing and novel hetero-structures, energy scales and relevant response functions for the interacting ground states found and information on tuning possibilities and material trends in these systems.

货车德瓦耳斯异质结构，特别是最新一波扭曲石墨烯系统的宏伟前景之一，是由电子相互作用驱动的物质的新相。相应地，这个研究项目的目标，放置在这个SPP的研究领域C，是提高我们的知识，在这些系统中的相互作用的影响，在一个双重的方法。一方面，我们希望探索双层和多层石墨烯范例之外的扭曲货车德瓦尔斯异质结构的丰富动物园。这将进行有效的低能量或少带模型的定性水平上获得的密度泛函理论的特征作为输入到无偏的方法，用于研究电子-电子的相关性。另一方面，我们将我们的研究扩展到包含整个大莫尔布里渊区，明确地在描述中保持更大跨度的高能自由度。这使我们能够作出预测，不能单独考虑费米能级附近的频带。这第二种方法，再次美联储与从头算输入获得的合作理论小组在这个优先计划，使我们有机会开发定量控制的结果，不可能受到复杂的强相互作用的影响，很容易发生在研究中限制在少数最低波段。最后，我们也可以使用这个计划的一个控制下折叠到有效的少带带模型，包括屏蔽效应超出随机相位近似。这些研究的预期成果包括现有和新型异质结构的相图，能量尺度和相关的相互作用基态的响应函数，以及这些系统中的调谐可能性和材料趋势的信息。