Collaborative Research: Parity-Time Symmetry and Anti-Symmetry in Quantum Optics

宇称和时间（PT）对称性是物理学基本定律的基础，在原子、分子、固态和高能物理学中得到了广泛的研究。最近，PT对称性已经成为光学研究的一个有趣的课题，并且作为一种多功能的资源，有望提供基于相干光学效应的传统系统所不提供的多种功能。然而，迄今为止，大多数研究都集中在经典光学上。该项目将在理论工作的指导下，进行实验尝试，研究量子光学中的PT和反PT对称性，预计在光学计算，安全通信等领域将出现广泛的新现象和应用机会。为此，将开发一个可扩展的纳米光子平台，以便项目成果可以迅速被量子计算，量子通信，单模激光等领域的广泛研究社区和工业利益相关者采用。该项目将由史蒂文斯理工学院和肯尼索州立大学的实验和理论研究人员合作进行。这两个研究所的学者和学生将接触到这一新的研究前沿，并鼓励他们跳出框框思考，例如为关键技术挑战寻求非传统的解决方案。通过史蒂文斯技术强化方案和与妇女参与工程方案和工程少数民族国家行动理事会等组织的机构联系，将向来自低收入和代表性不足群体的学生开展有重点的外联活动。在肯尼索，将为当地中小学学生举办一个物理日活动，通过动手示范展示科学和知识。除了通过出版物和会议演示进行标准的知识传播外，每年还将在两个研究所之间轮流举办向公众开放的量子科学和技术研讨会。基于锂离子纳米光子学和量子非线性光学技术，我们将研制一个用于探测PT和反PT对称下奇异量子动力学的芯片集成光学平台。通过将自发参量下转换与相敏放大相结合，在单光子水平上研究了PT对称性及其破缺相位的影响。量子反PT效应将使用三个渐逝耦合微环腔，一个具有强耗散，并通过测量所得的透射光谱和光子相关性进行探索。该项目的成功成果将加深对量子物理学中增益和损失的基本作用及其对开放量子系统的影响的理解，同时为该领域的几个突出问题提供实验见解。此外，PT和反PT对称性下的新量子现象可能会导致量子信息处理中几个关键挑战的优雅解决方案，包括由耗散和退相干引起的挑战。虽然目前的实验研究是专门研究一对基本的量子效应，但所开发的系统和技术已准备好用于其他光学和光子学的研究和应用。总的来说，这个合作项目将把PT和反PT研究扩展到量子光学的实验领域，并可能为量子科学和光学工程的新机会铺平道路。这个奖项反映了NSF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。

Parity and time (PT) symmetry underlies the fundamental laws of physics, and has been extensively studied in atomic, molecular, solid-state, and high-energy physics. Lately, PT symmetry has emerged as an interesting subject of optics research, and as a versatile resource promising a multitude of capabilities not offered by conventional systems based on coherent optical effects. Yet most studies thus far have been concentrated in classical optics. This project will make an experimental attempt, guided by theoretical efforts, to study PT and anti-PT symmetry in quantum optics, where a breadth of new phenomena and application opportunities are expected in optical computing, secure communications, and others. To this end, a scalable nanophotonic platform will be developed so that the project outcomes can be quickly adopted by broad research communities and industrial stakeholders in quantum computing, quantum communications, single mode laser, and others. The project will be carried out collaboratively by experimental and theoretical researchers from Stevens Institute of Technology and Kennesaw State University. Scholars and students in both institutes will get exposed to this new research front and encouraged to think outside the box, such as seeking unconventional solutions to critical technological challenges. Through the Stevens Technical Enrichment Program and institutional affiliations with organizations such as the Women in Engineering Program and the National Action Council for Minorities in Engineering, focused outreach activities will be made to students from low income and under-represented groups. At Kennesaw, a Physics Day program will be hosted for local elementary and middle school students with displays of science and knowledge through hands-on demonstrations. In addition to the standard knowledge dissemination via publications and conference presentations, quantum science and technology workshops open to public will be held yearly rotating between the two institutes. A chip-integrated optical platform for probing exotic quantum dynamics under PT and anti-PT symmetry will be developed based on lithium niobate nanophotonics and quantum nonlinear optics techniques. The effects of PT symmetry and its broken phase will be examined at a single photon level by linking spontaneous parametric down-conversion with phase sensitive amplification. The quantum anti-PT effects will be explored using three evanescently-coupled micro-ring cavities, one with strong dissipation, and by measuring the resultant transmission spectra and photon correlation. The successful outcomes of this project will deepen the understanding of the fundamental roles that gain and loss play in quantum physics and their implications for open quantum systems, while providing experimental insights to several outstanding questions in this field. Furthermore, the new quantum phenomena under PT and anti-PT symmetry may lead to elegant solutions to several key challenges in quantum information processing, including those caused by dissipation and decoherence. Although the present experimental research is to study specifically a couple of fundamental quantum effects, the developed systems and techniques are ready to be deployed for other optics and photonics research and applications. Overall, this collaborative project will extend PT and anti-PT studies to the experimental domain of quantum optics, and potentially pave a way to new opportunities in quantum science and optical engineering.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.