Novel Quantum Effects in Strongly Correlated Materials

该奖项支持研究和教育活动，旨在理解和预测量子材料中物质的新相，量子材料是具有大量粒子的物理系统，量子力学定律在其中得到更突出的体现。PI将研究电子以非常奇怪的方式运动的金属：在某些情况下，当它们在空间中向特定方向运动时，它们传播得好像没有质量；在其他情况下，它们以完全不连贯的方式运动，在极快的时间尺度上达到热平衡，这与铜或铝等传统金属不同。当它们在材料中传播时，电子可以形成具有最多样化性质的量子物质的相。电子相互作用的方式可以导致物质的新状态；从不能导电的金属到不耗散热量就能导电的超导体，甚至是电子像湍流一样流动的体制。该项目的理论进展将增强对物质的这些阶段的理解，并可能导致未来的设备技术和应用。该奖项还支持PI的外展活动，通过俄克拉何马大学的NSF本科生研究经验项目向本科生提供服务，并通过NSF教师研究经验项目向俄克拉何马城市区的高中物理教师提供服务。PI还将参加俄克拉何马州科学与数学学院的指导计划，这是俄克拉何马州首屈一指的公立寄宿高中，专注于科学、技术、工程和数学学科，并将向公众提供有关科学的公开讲座。该奖项支持研究和教育活动，旨在提高我们对广泛的强相关系统中的相互作用和新量子效应的基本理解，这些系统包含非常规准粒子或准粒子的概念完全不存在。研究将集中在两个主要方向：1)非常规金属的相关性，其中PI将探索具有节线半金属和半狄拉克费米子系统的新型量子临界现象和流体动力学行为，以及各种强相关电子系统中非相干金属的物理学及其与奇怪金属相的可能关系。2)云纹异质结构中的多体效应，PI将从理论上研究在魔角或魔角附近扭曲石墨烯双层中相互作用的物理特性，其中超导性和相关绝缘行为已在实验中观察到。研究小组将研究在量子临界点附近出现的新型向列超导相，Sachdev-Ye-Kitaev模型的推广，从实验响应函数的角度来看奇怪金属相的性质，以及在扭曲石墨烯双层中观察到的磁性和相关金属相。该奖项还支持PI的外展活动，通过俄克拉何马大学的NSF本科生研究经验项目向本科生提供服务，并通过NSF教师研究经验项目向俄克拉何马城市区的高中物理教师提供服务。PI还将参加俄克拉何马州科学与数学学院的指导计划，俄克拉何马州首屈一指的公立寄宿STEM高中，并将向公众提供有关科学的公开讲座。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NONTECHNICAL SUMMARY This award supports research and educational activities with an aim to understand and predict novel phases of matter in quantum materials, physical systems with a large number of particles where the laws of quantum mechanics are more prominently manifested. The PI will investigate metals where electrons can behave in very odd ways: In some cases they propagate as if they have no mass when they move in certain directions in space; in others, they move in a completely incoherent fashion, reaching thermal equilibrium at extremely fast time scales, unlike in conventional metals like copper or aluminum. As they propagate in materials, electrons can form phases of quantum matter with the most diverse properties. The way the electrons interact with each other can lead to novel states of matter; from metals that fail to conduct electricity to superconductors that conduct electricity without any dissipation of heat, or even regimes where electrons flow like a turbulent stream of water. The theoretical advances in this project will enhance the understanding of such phases of matter, and may lead to future device technologies and applications. This award also supports the PI's outreach activities to undergraduate students through the NSF Research Experience for Undergraduates program at the University of Oklahoma and to high school physics teachers in the metropolitan area of Oklahoma City through the NSF Research Experience for Teachers program. The PI will also enroll in the mentorship program at the Oklahoma School of Science and Mathematics, the premier public residential high school in the state of Oklahoma focused on Science, Technology, Engineering, and Mathematics disciplines, and will offer open lectures about science to the general public. TECHNICAL SUMMARY This award supports research and educational activities with an aim to enhance our fundamental understanding about interactions and novel quantum effects in a broad class of strongly correlated systems that host unconventional quasiparticles or where the concept of quasiparticles is entirely absent. The research will be focused on two main thrusts: 1) Correlations in unconventional metals, where PI will explore novel quantum critical phenomena and hydrodynamic behavior in systems with nodal-line semimetals and systems with semi-Dirac fermions, and the physics of incoherent metals and their possible relation to strange metal phases in various strongly correlated electron systems. 2) Many-body effects in Moire heterostructures, where the PI will theoretically examine the physics of interactions in twisted graphene bilayers at or near the magic angle, where superconductivity and correlated insulating behavior have been experimentally observed. The research team will investigate novel nematic superconducting phases emerging in the vicinity of quantum critical points, generalizations of the Sachdev-Ye-Kitaev model, the nature of strange metal phases from the point of view of experimental response functions, and the magnetic and correlated metallic phases observed in twisted graphene bilayers.This award also supports the PI's outreach activities to undergraduate students through the NSF Research Experience for Undergraduates program at the University of Oklahoma and to high school physics teachers in the metropolitan area of Oklahoma City through the NSF Research Experience for Teachers program. The PI will also enroll in the mentorship program at the Oklahoma School of Science and Mathematics, the premier public residential STEM high school in the state of Oklahoma, and will offer open lectures about science to the general public.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.