CAREER: Facets of gapless quantum matter: new phenomena, new tools, and new platforms

非技术总结这个职业奖项支持理论研究和教育，重点是了解固态材料中相互作用电子的组织以及当特定条件调整时其性质可能突然变化的非传统方式。理解电子组织及其变换的传统框架是基于对称性的概念，该概念本质上来自经典物理学中的直觉。近年来，人们已经意识到，电子的量子力学性质允许出现新的电子态，这种电子态因其所谓的“拓扑”性质而不同。例如，一些对称性相同的材料，如果不通过其块体导电，则可能具有电子态，使它们能够在其表面导电，但具有显著不同的表面导电性能。为了理解这些全新的电子态之间的转变，一个新的理论框架是必不可少的，一个整合了支配电子行为的量子力学原理的理论框架。这个项目的目的是深入研究在这些转变中可能发生的未知现象，制作创新的理论工具来了解它们的性质，并设计实验装置来测试这些新的物理概念。这项研究可能会导致对电子在材料中的不同行为的总体理解，并可能为下一代量子设备的材料平台奠定基础。该奖项还支持教育活动，包括指导研究生和博士后，以及开发新课程，重点是凝聚态理论中的现代技术。除了这些教育活动外，国际和平协会还将推出一项新的推广倡议，名为“量子回声：揭示物理学中的多元叙事”，这是一个开创性的口述历史项目，致力于放大物理界的不同声音。国际学生联合会将组织学生与代表不足的少数民族学生和教职员工进行口述历史访谈。该项目的使命是为年轻科学家，特别是代表不足的学生提供鼓励、灵感和指导的蓄水池，并使科学发现领域人性化。技术总结这个职业奖项支持理论研究和教育，专注于研究各种量子临界现象和量子多体系统中固有的无间隙相。理解无隙状态下的量子临界涨落提供了对其附近相及其有限温度性质的普遍理解。这些普遍的预测不仅在数学上是优雅的，而且很容易在实验中得到验证。Pi和他的团队将专注于以下方向：1)通过系统地构建拓扑相变模型来探索偏离Landau范式的相变的新现象，该模型展示了所谓的多路径量子临界，其中相同的相变可以有多条路径，每条路径都由不同的普适性类描述；2)开发创新的工具来表征强关联系统和非费米液态中的量子相变。PI将开发包含更复杂的低能涨落和对称性约束的广义网络模型，以描述具有强相互作用的晶体拓扑相以及具有空间和内部对称性的非费米液态之间的量子相变；以及3)设计实验平台，为深入探索强关联无间隙系统提供精度和控制。等电点分析表明，在一定条件下，扭曲的三层过渡金属二卤化物是实现MoiréKagome金属的理想体系。该奖项还支持教育活动，包括指导研究生和博士后，开发侧重于凝聚态理论现代技术的新课程。除了这些教育活动外，国际和平协会还将推出一项新的推广倡议，名为“量子回声：揭示物理学中的多元叙事”，这是一个开创性的口述历史项目，致力于放大物理界的不同声音。国际学生联合会将组织学生与代表不足的少数民族学生和教职员工进行口述历史访谈。该项目的使命是为年轻科学家，特别是代表不足的学生提供鼓励、灵感和指导的蓄水池，并使科学发现领域人性化。该奖项反映了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 CAREER award supports theoretical research and education focused on understanding the organization of interacting electrons in solid-state materials and the non-traditional ways in which their properties can change abruptly when specific conditions are adjusted. The traditional framework to understand electronic organizations and their transformations is based on the idea of symmetry, which in essence comes from intuition in classical physics. In recent years, it has been realized that the quantum mechanical nature of electrons allows for novel electronic states that differ by their so-called "topological" properties. For instance, some materials of the same symmetry that do not conduct electricity through their bulk can possess electronic states that allow them to conduct electricity on their surfaces, but with significantly different surface conducting properties. To comprehend the transitions between these fundamentally new electronic states, a fresh theoretical framework is essential, one that integrates the principles of quantum mechanics that dictate electron behavior. The aim of this project is to delve into the uncharted phenomena that can occur in these transformations, craft innovative theoretical tools to understand their properties, and design experimental setups to test these novel physics concepts. This research could lead to a general understanding of the diverse behavior of electrons in materials and potentially lay the groundwork for the material platforms for next-generation quantum devices.This award also supports educational activities which include mentoring graduate students and postdocs and developing new courses with emphasis on modern techniques in condensed matter theory. In addition to these educational activities, the PI will introduce a new outreach initiative named “Quantum Echoes: Uncovering Diverse Narratives in Physics”, a pioneering oral history project devoted to amplifying diverse voices in the physics community. The PI will organize students to conduct oral history interviews with underrepresented minority students and faculty members. The mission of the project is to provide a reservoir of encouragement, inspiration, and mentorship for young scientists, especially underrepresented students, and to humanize the realm of scientific discovery.TECHNICAL SUMMARYThis CAREER award supports theoretical research and education focused on the study of the diverse quantum critical phenomena and gapless phases inherent in quantum many-body systems. Understanding the quantum critical fluctuations in a gapless state provides a universal understanding of its nearby phases and their finite temperature properties. These universal predictions are not only mathematically elegant but also readily testable in experiments.The PI and his team will focus on the following directions: 1) Exploring novel phenomena for phase transitions diverging from Landau’s paradigm by systematically constructing models of topological phase transitions which demonstrate the so-called multi-path quantum criticality where the same phase transition can have multiple paths each described by a distinct universality class; 2) Developing innovative tools to characterize quantum phase transitions in strongly correlated systems and non-Fermi liquid states. The PI will develop generalized network models, encompassing more complex low energy fluctuations and symmetry constrains, to describe quantum phase transitions between crystalline topological phases with strong interactions as well as non-Fermi liquid states with spatial and internal symmetries; and 3) Designing experimental platforms that offer precision and control for an in-depth exploration of strongly correlated gapless systems. The PI will show that twisted trilayer transition metal dichalcogenides can be an ideal system to realize moiré Kagome metals within certain conditions. This award also supports educational activities which include mentoring graduate students and postdocs and developing new courses with emphasis on modern techniques in condensed matter theory. In addition to these educational activities, the PI will introduce a new outreach initiative named “Quantum Echoes: Uncovering Diverse Narratives in Physics”, a pioneering oral history project devoted to amplifying diverse voices in the physics community. The PI will organize students to conduct oral history interviews with underrepresented minority students and faculty members. The mission of the project is to provide a reservoir of encouragement, inspiration, and mentorship for young scientists, especially underrepresented students, and to humanize the realm of scientific discovery.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.