CAREER: Quantum State Preparation via Continuous Measurement and Feedback

了解量子系统的连续量子测量过程和实时反馈控制是量子信息科学的一个重要目标。这个CAREER项目的目标是通过实验实现量子测量理论的重要测试。在本基金资助的项目中，将进行一个腔量子电动力学（QED）反馈控制实验，以产生高精细腔模式的确定性光子数态。实现腔内光子数的连续非拆除测量，实时观察量子态约简到有条件的光子数状态。然后将采用量子反馈技术将连续测量稳定到确定性特征态。这一确定性态约简的演示将标志着我们为通信、计量和计算准备量子态的能力的巨大进步。最值得注意的是：一个单一的测量过程将能够产生不同的预定光子数，而不需要设计出精确的腔内激发数。研究量子测量和控制的基础将为适用于量子信息科学的一类典型状态制备技术提供必要的实验验证。量子态约简的完全连续观测有望为退相干、非幺正量子动力学和测量问题提供新的见解。该实验将有助于我们理解开放量子系统中的测量和反馈。提出的职业规划的教育发展方面集中在三个重要任务上：(1)通过将实验量子信息科学的最先进技术纳入本科，发现和教育将明确地整合到研究计划中。(2)在新墨西哥大学，绝大多数学生都住在校外，大约一半的学生都是通勤者，通过创建一个带有课程博客和视频聊天的虚拟会议室来应对这种情况，这样学生就可以像在校学生在做物理作业时那样进行交流。(3)参加西南科学教育研究院（SEIS），推动科学教育与学习。SEIS是桑迪亚国家实验室、新墨西哥大学和阿尔伯克基公立学校之间的一项合作努力，旨在加强从阿尔伯克基郊区到新墨西哥小普韦布洛的学校的教育。

An important goal of quantum information science is to understand the process of continuous quantum measurement and real-time feedback control of quantum systems. This CAREER project has the goal of experimentally implementing important tests of quantum measurement theory. In the project supported by this grant a cavity quantum electrodynamics (QED) feedback control experiment to generate deterministic photon number states of a high-finesse cavity mode will be conducted. Continuous nondemolition measurement of cavity photon number will be achieved and quantum state reduction to a conditional photon number state will be observed in real-time. Quantum feedback techniques will then be employed to stabilize the continuous measurement to a deterministic eigenstate. This demonstration of deterministic state reduction will signify a dramatic advance in our ability to prepare quantum states for communication, metrology and computation. Most notably: a single measurement procedure will be capable of generating different predetermined photon numbers, without engineering an exact number of intra-cavity excitations. Studying the foundations of quantum measurement and control will provide essential experimental validation of a canonical class of state-preparation techniques applicable to quantum information science. Complete continuous observation of quantum state reduction is expected to provide new insights into decoherence, non-unitary quantum dynamics and the measurement problem. The experiment will contribute to our understanding of measurement and feedback in open quantum systems.The educational development aspects of the proposed career plan are focused on three important tasks: (1) Discovery and education will be explicitly integrated in the research program by incorporating state-of-the-art techniques in experimental quantum information science into undergraduate. (2) Respond to the situation at the University of New Mexico, where the vast majority of students live off campus and around half of the students are commuters by creating a virtual conference room with a course blog and video chat that will allow students to have the kind of communication that on-campus students enjoy when working on physics assignments. (3) Participation in the Science Education Institute of the Southwest (SEIS) to advance science education and learning in . SEIS is a collaborative effort between Sandia National Laboratories, the University of New Mexico, and the Albuquerque Public Schools to enhance education in schools ranging from the Albuquerque outskirts to small New Mexico pueblos.