EAGER: The Fundamentals of Exotic Exciton Complexes in 2D Janus Semiconductors

Janus晶体是以双面罗马神命名的，是一类新的超薄二维材料。在这里，“Janus”这个名字来源于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。与Janus本身类似，Janus材料在纳米尺度上具有两种不同的原子排列方式。该理论告诉我们，这些材料具有相当非凡的光学、电学和磁性，并在量子工程、量子光学和自旋电子学的新技术方面显示出前景。但由于样品制备和测量技术的限制，我们对这些材料的理解仅局限于理论，没有任何实验见解。该项目旨在利用令人印象深刻的合成和表征技术了解Janus晶体的光学特性。接下来，它将采取措施将它们与其他量子平台集成，用于下一代光量子应用。与此同时，教育方面的努力为未来的K-12学生创造了全新的亚利桑那州立大学材料沉积/生长实验室之旅。该项目旨在研究过渡后金属硫族化物二维Janus层的光学性质，并将其与微腔集成，以稳定复杂的激子复合物，为新型量子应用奠定基础。最初的实验重点是合成外延级和激子级二维Janus晶体，并通过最先进的显微镜和光谱表征技术建立其光学特性。目标是建立这些材料的基本激子行为，如激子序列，激子结合能，偶极-偶极激子，以及当镜像对称被打破和层中存在巨大极化时的寿命。一旦建立，进一步的研究将集中在当这些二维Janus层与DBR微腔集成时玻色凝聚物或富激子复合物的形成和理解上。如果成功，该项目将首次提供对这些新型量子材料的实验见解。这项研究也为量子探测器、传感器和谷电子的众多应用的发展铺平了道路。首席研究员继续致力于大学内的推广、教育和合作努力，以及与凤凰城初中和高中、太阳魔鬼日和开放日活动以及技术实验室培训和参观。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。

Named after the two-faced Roman god, Janus crystals are a new class of ultrathin two-dimensional materials. Here, the name ''Janus'' originates from the ancient Roman God of beginnings and transitions with two faces one looking to the future while the other facing to the past. Similar to Janus himself, Janus materials have two different faces with two different atomic arrangement at the nanoscale. The theory tells us that these materials have rather extraordinary optical, electrical, and magnetic properties and show promise towards new technologies in quantum engineering, quantum optics, and spintronics. But our understanding of these materials are only limited to theory without any experimental insights due to limitations in sample preparation and measurement techniques. This project aims understanding the optical properties of Janus crystals using impressive synthesis and characterization techniques. Next, it takes steps to integrate them with other quantum platforms for next generation optical quantum applications. While doing so, the educational efforts create completely new lab tours to material deposition / growth labs at Arizona State University for prospective K-12 students.The project aims to investigate optical properties of post-transition metal chalcogenide 2D Janus layers and integrate them with microcavities to stabilize complex exciton complexes for new type of quantum applications. The initial experiments focus on the synthesis of epitaxial and excitonic grade 2D Janus crystals and establishing their optical properties through the state-of-the-art microscopy and spectroscopy characterization techniques. The goal is to establish the fundamental excitonic behavior of these materials such as excitonic series, exciton binding energies, dipolar-dipolar excitons, and lifetimes when the mirror symmetry is broken and large colossal polarization is present in the layer. Once established, additional studies focus on formation and understanding of Bose condensates or rich exciton complexes when these 2D Janus layers are integrated with DBR microcavities. If successful, the project provides the very first experimental insights into these new class of quantum material. This study also paves the way for development of numerous applications of quantum detectors, sensors, and valleytronics. The principal investigator continues to be committed to outreach, education and collaborative efforts within the university as well as with Phoenix middle and high schools, Sun Devil Days and Open House events and technical laboratory training and tours.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.