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

该职业奖支持理论研究和教育，重点是理解固态材料中相互作用电子的组织，以及在特定条件调整时其性质可能突然改变的非传统方式。理解电子组织及其变换的传统框架是基于对称性的思想，而对称性本质上来自经典物理学中的直觉。近年来，人们已经认识到，电子的量子力学性质允许通过所谓的“拓扑”属性不同的新型电子状态。例如，一些具有相同对称性但不通过其本体导电的材料可以拥有允许它们在表面导电的电子态，但表面导电特性却有很大不同。为了理解这些全新的电子状态之间的转变，一个新的理论框架是必不可少的，它集成了决定电子行为的量子力学原理。该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理解它们的特性，并设计实验装置来测试这些新颖的物理概念。这项研究可能会导致对材料中电子的各种行为的一般理解，并可能为下一代量子器件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，开发新的课程，重点是凝聚态理论的现代技术。除了这些教育活动外，PI还将推出一项名为“量子回声：揭示物理学中的多种叙事”的新推广计划，这是一个开创性的口述历史项目，致力于扩大物理界的各种声音。PI将组织学生与未被充分代表的少数民族学生和教师进行口述历史访谈。该项目的使命是为年轻科学家，特别是代表性不足的学生提供鼓励、灵感和指导，并使科学发现领域人性化。本职业奖支持理论研究和教育，重点研究量子多体系统中固有的各种量子临界现象和无间隙相。理解无间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特性的普遍理解。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朗道范式的相变新现象，这些模型证明了所谓的多路径量子临界性，其中相同的相变可以有多条路径，每条路径都由不同的普用性类描述；2)开发创新的工具来表征强相关系统和非费米液态的量子相变。PI将开发广义网络模型，包括更复杂的低能量波动和对称约束，以描述具有强相互作用的晶体拓扑相之间的量子相变以及具有空间和内部对称性的非费米液态；3)设计实验平台，为深入探索强相关无间隙系统提供精度和控制。实验结果表明，在一定条件下，扭曲三层过渡金属二硫族化合物可以成为实现Kagome金属相变的理想体系。该奖项还支持教育活动，包括指导研究生和博士后，开发新的课程，重点是凝聚态理论的现代技术。除了这些教育活动外，PI还将推出一项名为“量子回声：揭示物理学中的多种叙事”的新推广计划，这是一个开创性的口述历史项目，致力于扩大物理界的各种声音。PI将组织学生与未被充分代表的少数民族学生和教师进行口述历史访谈。该项目的使命是为年轻科学家，特别是代表性不足的学生提供鼓励、灵感和指导，并使科学发现领域人性化。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 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.