RUI: Multimode Quantum State Tomography of Stored Photons

量子信息可以从光束转移到原子云，并在稍后的时间可控地释放。这个过程形成了许多重要的量子存储设备的基础，这些设备对量子信息科学、量子计算和量子通信的未来至关重要。先前的实验已经将光存储在各种系统中，包括冷原子云、热原子蒸气、固态材料和光纤。为了扩展这些成功的研究，该计划的目标是对存储和检索多模光的量子态进行全面表征。太平洋大学的Dawes博士将量子态重建技术应用于实验存储光系统。其结果是更完整地了解光在存储前后的量子态。现有的检测方案不能区分检索过程中的损失和检测过程中的损失。特别地，如果由检测器选择的空间模式不同于携带取回的光的空间模式，则单模检测遭受损失。阵列探测器同时测量所有空间模式。该能力可用于最大化取回的光子的数量，并允许计算和优化取回的空间模式。因此，阵列检测比以前的方法恢复更多的光量子态信息。阵列检测也用于比较多个检索到的模式，并探索模式之间的相关性。这一新信息的重要性在于它揭示了量子存储过程的基本特性。该项目的科学承诺是，它将基于存储量子态的表征，对存储光过程产生新的理解。由于这些过程是量子存储器设备的基础，这些设备被广泛研究，这一承诺具有相当大的价值。在原子蒸气系统中的这些研究结果将为未来使用固态材料的多模量子存储器的研究提供信息。但是，除了研究竞技场的直接进步之外，这个项目还培训了本科生，并激励他们考虑从事科学事业。本科研究人员参与项目的每一步，并获得实验设计，数据收集，分析和传播的经验。在此期间获得的技术技能，在支持性的研究社区的细心指导相结合，创造科学孵化器的最佳形式，为学生成功的科学事业做好准备。在区域和国家会议的出席和演讲为学生提供了进一步深入了解科学专业，以及扩大他们的同行网络的机会。此外，学生参加了一个新的五所学校的原子，分子和光学物理研究小组在太平洋西北部。

Quantum information can be transferred from a beam of light to a cloud of atoms and controllably released at a later time. This process forms the basis of many important quantum memory devices that are fundamental to the future of quantum information science, quantum computing, and quantum communication. Prior experiments have stored light in a variety of systems, including cold atom clouds, warm atomic vapor, solid state materials, and optical fibers. To extend these successful investigations, the goal of this program is to carry out a full characterization of the quantum states of stored-and-retrieved multimode light.Dr. Dawes at Pacific University applies techniques developed for quantum state reconstruction to experimental stored-light systems. The result is a more complete understanding of the quantum state of light before and after storage. Prior detection schemes cannot distinguish between losses in the retrieval process and losses in the detection process. In particular, single-mode detection suffers from losses if the spatial mode chosen by the detector differs from the spatial mode carrying the retrieved light. Array detectors measure all spatial modes simultaneously. This capability can be used to maximize the number of retrieved photons and allows for computation and optimization of the retrieved spatial mode. Array detection therefore recovers more information on the quantum state of light than previous methods. Array detection is also used to compare multiple retrieved modes, and to explore correlations between modes. The importance of this new information is that it reveals fundamental properties of the quantum memory process.The scientific promise of this project is that it will create a new understanding of stored light processes based on the characterization of stored quantum states. Since these processes are fundamental to quantum memory devices, devices which are widely studied, this promise is of considerable value. Results from these studies in atomic vapor systems will inform future research in multimode quantum memories using solid state materials. But more than the immediate advances in the research arena, this program also trains undergraduates and inspires them to consider careers in science. Undergraduate researchers participate in every step of the project, and gain experience with experiment design, data collection, analysis, and dissemination. The technical skills acquired during this experience, combined with attentive mentoring in a supportive research community, create the best form of scientific incubator to prepare students for successful science careers. Attendance and presentations at regional and national conferences provide students with further insight into the scientific profession, as well as an opportunity to expand their network of peers. Additionally, students participate in a new five-school consortium of atomic, molecular, and optical physics research groups in the Pacific Northwest.