Collaborative Research: Correlated States in Twisted Hetero-bilayer Transition Metal Dichalcogenides

非技术摘要：在传统材料中，电子在原子的周期性阵列中移动，而不会彼此“交谈”（相互作用）。当两个原子级薄材料的单层（也称为二维（2D）材料）堆叠在一起时，这两层之间的扭曲角得到了很好的控制，它们形成了一种具有有趣特性的新的周期性结构。在这个合作项目中，PI研究这些2D材料，以获得可以实现变革性技术创新的知识，如高温超导，量子电子学和光电子学。该项目整合了一个教育部分，以培训学生并为量子科学和技术建立一支强大的劳动力队伍。技术摘要：相关态如莫特绝缘体和维格纳晶体仍然是物理学中有趣的课题。最近，扭曲的异质双层过渡金属二硫属化物（TMD）已经成为一个新的平台，具有更强的相关强度，其强的自旋轨道耦合和带隙的存在提供了新的途径，探索自旋相关的物理学和相关态的光电子学。在这项合作计划中，PI探索了由扭曲的异质双层TMD形成的莫尔超晶格。这项研究计划包括两个主要方面。第一个目标是描述关联态的相互作用强度，并研究它与莫尔结构参数和操纵关联态的外部控制的关系。第二个重点是探索与其他电子相相互作用产生的新关联态，例如关联态与朗道能级的相互作用，强关联对莫尔超晶格的谷物理和激子物理的影响，以及在这种强相互作用系统中可能出现的其他类型的新态。该合作项目培训研究生和本科生，为未来在量子科学和技术方面的工作提供培训。该项目还为K-12学生建立了研究模块，并积极参与代表性不足的群体。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Nontechnical Abstract: In conventional materials, electrons travel in the periodic arrays of atoms without "talking" (interacting) to each other. When two monolayers of atomically thin materials, also knowns as two-dimensional (2D) materials, are stacked together with a well-controlled twist angle between these two layers, they form a new periodic structure with interesting properties. In this collaborative project, the PIs investigate these 2D materials to gain knowledge that could enable transformative technology innovations such as high-temperature superconductivity, quantum electronics and optoelectronics. This project integrates an education component to train students and build a strong workforce for quantum science and technologies. Under-represented groups are particularly encouraged and included in the education programs.Technical Abstract: Correlated states such as Mott insulators and Wigner crystals remain intriguing subjects of physics. More recently, twisted hetero-bilayer transition metal dichalcogenides (TMDs) have emerged as a new platform with even more enhanced correlation strength, and their strong spin-orbit coupling and presence of bandgaps provide new avenues to explore spin-related physics and optoelectronics in correlated states. In this collaborative proposal, the PIs explore the moiré superlattices formed by twisted hetero-bilayer TMDs. The research plan includes two main thrusts. Thrust I is to characterize the interaction strength of the correlated states and study its relationship with moiré structure parameters and external controls to manipulate the correlated states. Thrust II is to explore new correlated states arising from interactions with other electronic phases, such as the interplay of correlated states with Landau levels, the effect of strong correlation on valley physics and excitonic physics of the moiré superlattice, and other types of new states that could possibly arise in this strongly interacting system. The collaborative project trains graduate and undergraduate students are trained for future placement in quantum science and technologies. The project also creates research modules for outreach to K-12 students and actively involves under-represented groups.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.