CAREER: Correlated Excitons in Semiconducting Moire Superlattices

职业：半导体莫尔超晶格中的相关激子

• 批准号: 2337606
• 负责人: CHENHAO JIN
• 金额: $ 75.03万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2029-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2337606&HistoricalAwards=false
• 关键词: CAREER; Correlated; Excitons; Semiconducting; Moire

Non-technical abstract:Fundamental particles can be classified into fermions and bosons, which have distinct collective behaviors. Interactions between electrons, a fermion, results in now well known emergent properties. On the other hand, creation of unconventional bosonic matter has been challenging since bosons in natural materials are often weakly-interacting and/or short-lived. This project bridges this gap by creating unconventional bosonic matter using excitons in semiconducting moiré superlattices. Compared to existing platforms such as cold atoms and quantum wells, this platform offers orders-of-magnitude higher temperature scale (tens of Kelvin vs. 1 Kelvin) and scalability (10000 particles vs. ~100 particles). Research is incorporated into a broad outreach plan under the theme of “Science as a Lego game”. Leveraging the Lego-like nature of optical setups, integrated outreach activities are targeted at students at many educational levels to demystify quantum science and introduce them to potential career options. Specific activities include designing a high-school lab-based class series on building optical modules and a Saturday class on optics in quantum science; initiating a summer research intern program for undergraduate students; and organizing a quantum science summer school for graduate students and postdocs.Technical abstract:Condensed matter physics aims to understand how interactions endow simple elementary particle building blocks with complex emergent phenomena. Exotic quantum phases of fermionic electrons have been intensively studied in solid-state systems, including recently in moiré superlattices. However, collective bosonic states have remained the purview of ultra-cold atoms due to the lack of suitable condensed matter platforms and experimental probes. This project aims to overcome both challenges and establishe excitons in semiconducting moiré superlattices -- bosons composed of tightly bound electron-hole pairs -- as a platform for engineering exotic collective states of interacting bosons. The principal investigator is developing a set of novel pump- probe spectroscopies that enables direct measurement of exciton compressibility, isolating low energy “charge” and “spin” excitations of excitons, as well as investigating their dynamics. This allows identification and investigation of a plethora of exotic bosonic phases such as bosonic Wigner crystal, Mott-superfluid transition, valley pseudospin exchange interactions and pseudospin orders, etc. This project forges a path to a new class of “quantum exitonic materials” where exotic properties and novel device concepts arise from strongly correlated bosons, thereby establishing a new fundamental pillar of condensed matter alongside the extensively studied quantum electronic materials.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.

非技术摘要：基本粒子可分为费米子和玻色子，电子（费米子）之间的相互作用具有不同的集体行为，导致现在众所周知的涌现特性。天然材料中的玻色子通常是弱相互作用和/或短暂的，该项目通过使用激子创建非常规玻色子物质来弥补这一差距。与现有平台（例如冷原子和量子阱）相比，该平台提供了高几个数量级的温标（数十开尔文与 1 开尔文）和可扩展性（10000 个粒子与约 100 个粒子）。综合外展活动以“科学作为乐高游戏”为主题，利用光学装置的乐高性质，针对不同教育程度的学生开展综合外展活动。揭开量子科学的神秘面纱，并向他们介绍潜在的职业选择，包括设计一个关于构建光学模块的高中实验室系列课程和一个关于量子科学光学的周六课程；为本科生启动和组织暑期研究实习计划；为研究生和博士后开设的量子科学暑期学校。技术摘要：凝聚态物理学旨在了解相互作用如何赋予简单的基本粒子构建块以复杂的涌现现象。然而，由于缺乏合适的凝聚态平台和实验探针，集体玻色子态仍然是超冷原子的研究范围，该项目旨在克服这两个挑战并在半导体中建立激子。莫尔超晶格——由紧密束缚的电子空穴对组成的玻色子——作为设计相互作用玻色子的奇异集体态的平台首席研究员正在开发一套新颖的泵浦探针。光谱学能够直接测量激子压缩性，隔离激子的低能“电荷”和“自旋”激发，以及研究它们的动力学，这使得可以识别和研究大量奇异的玻色子相，例如玻色子维格纳晶体、莫特-超流跃迁、谷赝自旋交换相互作用和赝自旋有序等。该项目开辟了一条通向新型“量子激子材料”的道路，其中具有奇特的特性和新颖的器件概念源自强相关玻色子，从而在所研究的量子电子材料旁边建立了凝聚态物质的新基本支柱。该奖项反映了 NSF 的法定使命，并通过使用基金会的普遍智力价值和更广泛的影响审查标准进行评估，被认为值得支持。