Bosonic Condensation and Emergent Phenomena in 2D Janus layers and Moiré Lattices

最近发现的Janus材料是一类新的超薄晶体。在这里，“Janus”这个名字来自古罗马的开始和过渡之神，他有两张脸，一张面向未来，另一张面向过去。像Janus一样，Janus材料的顶面和底面由不同的原子组成。这种独特的原子排列为下一代量子技术带来了有前途的光学特性，特别是如果人们管理材料与光之间的强相互作用。该项目旨在通过将这些材料封装在一个特殊的镜子（布拉格反射器）中来发现新的量子特性，该镜子旨在捕获光并实现强的光-材料相互作用。在这样做的同时，提出了一个创新的教育计划，以培养本科生和高中生在一个积极的研究环境，创造下一代的科学和工程劳动力。与此同时，教育计划引入了“生活在材料世界”外展活动，通过每月和每季度的在线和现场实验室图尔斯，演示和辅导活动，刺激和准备K12学生在科学和工程的职业生涯。这些玻色子准粒子具有非常吸引人的性质和功能，这是单独使用激子无法实现的。如果激子-极化激元的密度增加到足以形成极化激元玻色凝聚体，那么激发新的材料特性是可能的。在这里，由于巨大的偶极矩和偶极激子的存在，Janus层提供了延长的激子寿命，奇异的谷物理学和非线性特性，这些特性对于达到这种量子状态是理想的。因此，该项目的第一个目标是通过将2D Janus层封装在设计的高Q因子微腔中来稳定强耦合机制中的激子-极化激元。系统的研究下一步的目标是证明玻色极化激元凝聚在高密度制度，并建立其量子特性。最后，研究小组研究了拓扑激子的形成，控制了超辐射相的形成，并通过使用它们的莫尔晶格和调整其潜在的景观来探索玻色-哈伯德物理学的新机制。一旦完成，引入的Janus和Moiré激子-极化激元，极化激元凝聚体和拓扑激子预计将填补该领域的一个巨大的基础知识空白。潜在的社会影响包括高温极化激子激光器和新的量子信息设备，以及高中和本科生的教育培训活动。该奖项反映了NSF的法定使命，并通过使用基金会的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。

Non-Technical AbstractRecently discovered Janus materials are a new class of ultra-thin crystals. Here, the name ''Janus'' comes from the ancient Roman God of beginnings and transitions with two faces one looking to the future while the other facing to the past. Like Janus himself, Janus materials have top and bottom faces made of different atoms. This unique atomic arrangement brings promising optical properties towards next-generation quantum technologies, especially, if one manages strong interaction between materials and light. This project aims to discover new quantum properties by encapsulating these materials within a special mirror, a Bragg reflector, designed to trap light and achieve strong light-material interaction. While doing so, an innovative educational plan is proposed to train the undergraduate and high school students in an active research environment to create next-generation science and engineering workforce. In parallel, the educational plan introduces ‘Living in a Materials World’ outreach activity to stimulate and prepare K12 students for careers in sciences and engineering through monthly and quarterly online and in-person lab tours, demonstration, and tutorial events.Technical AbstractRecent studies have demonstrated exciton-polaritons in two-dimensional excitonic dichalcogenides. These bosonic quasi-particles have highly appealing properties and functionalities that are not accessible with excitons alone. Exciting new material properties are possible if the density of exciton-polaritons is sufficiently increased to form polariton Bose condensates. Here, owing to the presence of colossal dipole moment and dipolar excitons, Janus layers offer extended exciton lifetimes, exotic valley-physics, and non-linear properties that are ideal for reaching this quantum regime. As such, this project first aims to stabilize exciton-polaritons in the strong-coupling regime by encapsulating 2D Janus layers in designer high-Q factor microcavities. Systematic studies next aim to demonstrate Bose polariton condensates in the high-density regime and establish their quantum properties. Lastly, the research team investigates the formation of topological excitons, controls the super-radiant phase formation, and explores new regimes of Bose-Hubbard physics by using their Moiré lattices and tuning its potential landscape. Once completed, the introduced Janus and Moiré exciton-polaritons, polariton condensates, and topological excitons are anticipated to fill a large fundamental knowledge gap in the field. Potential societal impacts include high-temperature polaritonic lasers and new quantum information devices as well as educational training activities for high school and undergraduate students.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.