Photophysics of Colloidal Semiconductor Nanoplatelets Relevant to Quantum Optics

在化学系大分子、超分子和纳米化学项目的支持下，罗切斯特大学的托德·克劳斯教授和他的学生将探索单光子光和物质相互作用的新方法，将化学带入一个被称为量子光学的领域。量子科学中的一个长期存在的问题是，为了维持量子行为，系统需要在超低温下运行，而这通常并不实用。然而，在室温下，热能产生的随机振动会导致基于物质的量子系统彼此不同步，从而破坏整个量子态。由于光不受热效应的影响，光的单光子在室温下具有很大的潜力来保持状态的量子性质。不幸的是，在实践中，人们并不普遍知道如何以这种方式利用光来保存量子态。该项目将接受这一挑战，同时帮助培养下一代量子信息科学家，包括通过夏季本科生研究伙伴计划支持增加STEM(科学、技术、工程和数学)劳动力的种族和民族多样性。该团队还通过在罗切斯特博物馆和科学中心的推广工作，在量子科学领域引起了公众的兴奋。该项目的总体目标是对CdSe纳米板(NPL)的光物理性质，如激子相干性和单光子发射的纯度，建立一个详细和完整的基础了解，这些都与量子科学中的光子应用有关。每个纳米粒子的巨大吸收强度、大面积表面上定义良好的表面化学、原子表面平坦的表面以及高效的光致发光(PL)使得CdSe非发光材料在量子光学中具有潜在的应用前景。为了促进对NPL光物理性质的了解，人们正在追求两个具体的目标：1)表征与单光子量子发射相关的核-冠结构的CdSe NPLs的光物理性质；以及2)建立单个掺Ag+的CdSe NPLs的物理形态和光子发射性质之间的关系，直至单光子水平。通过这些研究，本项目旨在加深对NPL的物理、形态和化学性质如何影响其单光子发射特性的理解。如果成功，该项目可以为该领域提供一个基于胶体CdSe NPL产生明亮和稳定的单光子发射器的路线图，这对基于室温量子技术的未来发展至关重要。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。

With support from the Macromolecular, Supramolecular and Nanochemistry program in the Chemistry Division, Professor Todd Krauss and his students at the University of Rochester will explore new ways to interface single photons of light and matter, bringing chemistry into a field known as quantum optics. A longstanding problem in quantum science concerns the requirement for systems to operate at ultracold temperatures in order to maintain quantum behavior, which is not generally practical. At room temperature, however, the random vibrations arising from heat energy causes matter based quantum systems to get out of step with each other, ruining the overall quantum state. Single photons of light have significant potential for preserving the quantum nature of states at room temperature because light is not affected by thermal effects. In practice, unfortunately, it is not generally known how to use light in this manner to preserve quantum states. This project will take on this challenge while also helping to train the next generation of quantum information scientists, including supporting the increase of racial and ethnic diversity of the STEM (science, technology, engineering and mathematics) workforce through a summer undergraduate student research partnership program. The team is also generating public excitement in quantum science through outreach efforts at the Rochester Museum and Science Center. The overall goal of this project is to develop a detailed and complete, fundamental understanding of the photophysical properties of CdSe nanoplatelets (NPLs), such as exciton coherence, and the purity of single photon emission, which are relevant for photonic applications in quantum science. The giant absorption strength per nanoparticle, well defined surface chemistry on the large area faces, atomically flat surfaces, and efficient photoluminescence (PL) make CdSe NPLs very attractive for potential applications in quantum optics. Two specific aims are being pursued with the aims of advancing knowledge of NPL photophysical properties: 1) characterizing the photophysical properties of core-crown CdSe NPLs relevant to single photon quantum emission; and 2) establishing the relationship between physical morphology and photon emission properties for individual CdSe NPLs doped with Ag+ down to the single photon level. Through these studies, this project aims to develop an understanding of how the physical, morphological, and chemical properties of NPLs impact their single photon emission characteristics. In successful, this project could provide the field with a roadmap for generating bright and stable single photon emitters based on colloidal CdSe NPLs, which is essential for the future development of room temperature quantum-based technologies.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.