CAREER:Superconductivity, fractionalization and quantum criticality in multilayer quantum simulator

非技术总结该奖项支持探索新量子材料的理论研究和教育活动。这些项目使用原子薄的二维材料作为构建块。一种典型的二维材料是石墨烯，它由以蜂窝形式排列的单层碳原子组成。在材料内部，许多电子一起运动，并相互作用强烈。量子效应和电子之间的强关联的结合可以产生具有有趣的材料性质和潜在的技术应用的新型相。例如，当超导体材料冷却到足够低的温度时，它可以零电阻地传导电流。一些量子材料可能被用来建造量子计算机。PI将开发各种策略，通过将二维材料堆叠在一起形成多层系统来实现新的量子相。多层材料不仅具有单层材料所没有的新特性，而且能够更好地对材料特性进行实验控制和表征。该奖项还支持PI的教育和外展活动。该奖项将(1)将本科生纳入研究计划并主持非正式期刊俱乐部研讨会，(2)开发新的课程材料以纳入现代研究主题，(3)邀请来自巴尔的摩市服务不足地区的公立高中的学生参与研究。技术总结该奖项支持理论研究和教育活动，以探索新的量子相，这些量子相可以出现在多层系统中，这些量子相可以通过将基本的二维层堆叠成“乐高积木”而建立起来。这些项目将利用最近的能力，利用这种材料中的层自由度。我们将使用各种理论和数值方法，包括部分子平均场理论、量子场理论和密度矩阵重整化群(DMRG)模拟。这些研究将与三个不同平台上正在进行和即将进行的实验密切合作：(1)双层莫尔超晶格中物质的新相及其实验特征；(2)量子霍尔双层中的量子临界性和非阿贝尔分数相；(3)双层光学晶格中的增强超导电性和Kondo相变。该项目将为强关联模型开发新的理论框架和数值方法，通过正在进行的和不久的将来的量子模拟实验进行基准和完善。该项目可能有助于更好地了解高温超导体的机制，并开发新的拓扑量子计算平台。这项提议将研究与支持多样性、教育和社区推广紧密联系在一起。该计划将为“凝聚态物理”课程开发新的课堂讲稿和课程材料，以纳入现代研究主题，如能带拓扑和扭曲的双层石墨烯。PI将把本科生纳入研究计划，并通过举办非正式的期刊俱乐部研讨会来鼓励本科生、研究生和博士后之间的交流。PI还将邀请来自巴尔的摩市服务不足地区的公立高中的学生参与研究。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NONTECHNICAL SUMMARYThis award supports theoretical research and education activities to explore new quantum materials. The projects utilize atomically thin two-dimensional materials as building blocks. A typical two-dimensional material is graphene, which consists of a single layer of carbon atoms arranged in the form of honeycomb. Inside the material, many electrons move together and strongly interact with each other. Combination of quantum effects and strong correlations between electrons can lead to novel phases with interesting material properties and potential technology applications. For example, a superconductor material can conduct electric current with zero resistance when it is cooled to sufficiently low temperature. Some quantum materials may be utilized to build a quantum computer. The PI will develop various strategies to realize new quantum phases by stacking two dimensional materials together to form multilayer systems. The multilayer materials not only have new properties unseen in the single layer case, but also enable better experimental control and characterization of the material properties.This award also supports the PI’s education and outreach activities. The PI will (1) include undergraduate students in the research program and host informal journal club seminar, (2) develop new course materials to incorporate modern research topics and (3) engage students from public high schools from underserved areas in Baltimore City in research.TECHNICAL SUMMARYThis award supports theoretical research and education activities to explore novel quantum phases which can emerge in multilayer systems built from stacking the elementary two-dimensional layers as “Lego sets”. These projects will take advantage of the recent capability to exploit the layer degree of freedom in such materials. Various theoretical and numerical methods will be utilized, including parton mean field theory, quantum field theory and density-matrix-renormalization-group (DMRG) simulations. The studies will work closely with on-going and near future experiments in the three different platforms: (1) Novel phases of matter and their experimental signatures in bilayer moire superlattices; (2) Quantum criticality and non-Abelian fractional phases in quantum Hall bilayers; (3) Enhanced Superconductivity and Kondo transition in bilayer optical lattice.The project will develop new theoretical frameworks and numerical methods for strongly correlated models, benchmarked and refined by ongoing and near future quantum simulation experiments. The project can potentially lead to better understanding of the mechanism towards high temperature superconductors and development of new platforms for topological quantum computation.This proposal closely links research with support for diversity, education and community outreach. The proposal will develop new lecture notes and course materials for the course ‘Condensed Matter Physics’ to include modern research topics such as band topology and twisted bilayer graphene. The PI will include undergraduate students in the research program and encourage communications between undergraduate students, graduate students and postdocs by hosting an informal journal club seminar. The PI will also engage students from public high schools from underserved areas in Baltimore City in research.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.