Harnessing Quantum Entanglement for Quantum-Enhanced Sensing through Interaction-Based Readout

纠缠是一种量子现象，通过这种现象，系统的不同部分变得密不可分，无法在物理上独立描述。纠缠是开发新的量子增强技术的关键资源，与牛顿和伽利略的经典物理学所描述的当前设备相比，这些技术承诺在性能上有惊人的改进。例如，量子增强型传感器利用纠缠放大由于重力、电磁场或周围环境的微弱变化而对量子系统产生的微小扰动，其应用范围从工业到基础科学，从工业到基础科学，都可以用来超精确地搜索标准模型以外的物理。然而，量子增强传感前沿的一个关键挑战是开发简单而实用的方法来表征纠缠量子系统的这些微扰。这个研究项目试图了解如何通过使用基于相互作用的读出(IBR)来克服这一问题，其中由量子系统的组成粒子之间的相互作用引起的复杂动力学被用作内在的内部探针。所进行的工作将促进基础科学的进步，因为开发现实和强大的IBR方法，将与使用纠缠量子系统相关的技术挑战降至最低，对于实现具有现实世界应用的最先进传感器非常重要。此外，该研究还为参与研究的学生和博士后研究员提供了宝贵的技术培训机会，为STEM劳动力和经济做出了贡献。该项目的总体目标是建立一个理论框架，用简单的测量探针为量子增强传感的最佳IBR方案建立一个理论框架。这一核心的智能任务将通过两个相互关联的主题的IBR方案的研究来实现：i)使用纠缠基态的量子传感，以及iii)混沌量子传感器。第一个主题将寻求设计最佳的IBR方案，以利用准绝热演化产生的纠缠基态用于量子增强计量学，考虑到测量和动力学控制的现实实验限制，并确定导致实际量子优势的最佳运行机制。后一个主题研究IBR如何作为一种使能工具来驾驭和表征由多体量子混沌产生的复杂纠缠态，核心重点是开发策略来克服有害的退相干和降低纠缠的技术噪声。通过扩大非平衡和准平衡系统的范围，在这些情况下更好地理解IBR方案，将产生立竿见影的效果，这些系统可以实际用于量子增强的传感和技术。这一奖项反映了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。

Entanglement, a quantum phenomena whereby distinct parts of a system become inextricably linked and cannot be physically described independently, is a key resource in the development of new quantum-enhanced technologies that promise astounding improvements in performance compared to current devices describable by the classical physics of Newton and Galileo. Examples include quantum-enhanced sensors that use entanglement to amplify small perturbations to quantum systems due to weak changes in gravity, electromagnetic fields or the surrounding environment, and which can have applications ranging from industry, where they can be used in searches for natural resources, to fundamental science, where they can enable ultra-precise searches for physics beyond the standard model. Nevertheless, a key challenge in the frontier of quantum-enhanced sensing is the development of simple and practical ways to characterize these perturbations of entangled quantum systems. This research project seeks to understand how to overcome this problem by using "interaction-based readout" (IBR), wherein the complex dynamics induced by interactions between constituent particles of a quantum system is used as an intrinsic internal probe. The work conducted will promote the progress of basic science, as developing realistic and robust IBR approaches which minimize technical challenges associated with using entangled quantum systems can be important for the realization of state-of-the-art sensors with real world applications. Moreover, the research provides valuable technical training opportunities for participating students and a post-doctoral researcher, contributing to the STEM workforce and economy.The overall goal of the project is to establish a theoretical framework for optimal IBR schemes for quantum-enhanced sensing with simple measurement probes. This core intellectual task will be approached by investigation of IBR schemes in two inter-related topics: i) quantum sensing using entangled ground-states, and iii) chaotic quantum sensors. The first topic will seek to devise optimal IBR schemes to exploit entangled ground states generated by quasi-adiabatic evolution for quantum-enhanced metrology, taking into account realistic experimental limitations on control of measurements and dynamics, and identifying optimal regimes of operation that lead to a practical quantum advantage. The latter topic studies how IBR can serve as an enabling tool to harness and characterize complex entangled states generated via many-body quantum chaos, with a core focus on developing strategies to overcome deleterious decoherence and technical noise that degrades entanglement. Developing an improved understanding of IBR schemes in these scenarios will have immediate impact by broadening the scope of non-equilibrium and quasi-equilibrium systems that can be practically exploited for quantum-enhanced sensing and technology.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.