Photophysics of Colloidal Semiconductor Nanoplatelets Relevant to Quantum Optics

在化学学部大分子、超分子和纳米化学项目的支持下，罗切斯特大学的Todd Krauss教授和他的学生将探索将单光子与物质结合的新方法，将化学引入量子光学领域。量子科学中一个长期存在的问题是，为了保持量子行为，系统需要在超冷的温度下运行，这通常是不现实的。然而，在室温下，由热能引起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，单光子具有在室温下保持态的量子性质的巨大潜力。不幸的是，在实践中，人们通常不知道如何以这种方式利用光来保持量子态。该项目将接受这一挑战，同时也将帮助培养下一代量子信息科学家，包括通过暑期本科生研究合作计划支持STEM（科学、技术、工程和数学）劳动力的种族和民族多样性的增加。该团队还通过在罗切斯特博物馆和科学中心的推广工作，引起了公众对量子科学的兴趣。该项目的总体目标是对CdSe纳米片（NPLs）的光物理性质（如激子相干性和单光子发射纯度）有一个详细、完整、基本的了解，这与光子在量子科学中的应用有关。每纳米粒子的巨大吸收强度，大面积表面上明确的表面化学性质，原子平面，以及高效的光致发光（PL）使CdSe npl在量子光学中的潜在应用非常有吸引力。为了提高对NPL光物理性质的认识，有两个具体的目标：1)表征与单光子量子发射相关的核冠CdSe NPL的光物理性质；2)建立了单个掺杂Ag+的CdSe NPLs的物理形态与光子发射特性之间的关系。通过这些研究，本项目旨在了解不良物质的物理、形态和化学性质如何影响它们的单光子发射特性。如果成功，该项目可以为该领域提供基于胶体CdSe NPLs产生明亮和稳定的单光子发射器的路线图，这对未来室温量子技术的发展至关重要。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。

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.