Photon Temporal Modes as a Quantum Information Resource

作为量子信息资源的光子时间模式

• 批准号: 1521466
• 负责人: Michael Raymer
• 金额: $ 47.5万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1521466&HistoricalAwards=false
• 关键词: Photon; Temporal; Modes; Quantum; Information

Quantum information science (QIS) promises means for storing, transmitting, and processing information in ways not achievable using conventional (classical-physics-based) information technology. Success in QIS could revolutionize both technology and science through new computation and communication capabilities. Major breakthroughs are still needed before these can become reality. It is generally recognized that the most powerful quantum computation will take place using material systems (atoms or electrons). In contrast, quantum communication across a network (a "Quantum Internet") will take place using light (photons). In addition, specialized quantum-information processing will take place using light or a combination of light and interacting atoms, as needed, for example, to construct signal repeaters for extending the range of quantum communication over longer distances. This project will develop a radical, yet practical, new approach to using photons to encode quantum information.Photons in a light beam have four distinct properties, any of which could be used to encode quantum-information: polarization (e.g., vertical or horizontal), two-dimensions of beam profile (spatial shape), and temporal shape (variation in time of brightness during a light pulse). In order to fully utilize light for transmitting information in a quantum network, it is necessary to be able to manipulate and sort a beam of light according to the states associated with each of these properties. While polarization and spatial beam profiles have been previously developed as means for encoding quantum information on photons, the temporal shape of photons has gone largely unrecognized as an important potential technique. The project endeavors to complete the "tool kit" for photon-based QIS by developing means to use photon temporal shape to encode information. This approach has predicted benefits in that 1) it allows more than one bit of information to be encoded on a single photon, 2) the encoding method is robust against the alterations of light that occur while traveling in a long optical fiber, and 3) the method nicely interfaces with atom-based quantum-light memories, which will be used in the future construction of a Quantum Internet. Controlling quantum systems is of broad interest in science and information technology, metrology, quantum chemistry, and nano-mechanics. Optical technology and quantum-optics-based information science offer excellent opportunities to integrate research with science education. To improve the quality of general science education for non-science majors, the P.I. cofounded in 2010 the Science Literacy Program (SLP) at the University of Oregon, and serves as its Co-Director. The SLP has provided mentored instructional opportunities to many graduate students and undergraduate science majors serving as co-instructors in science literacy courses. He developed and taught an SLP course, Quantum Physics for Everyone, which presented quantum information science to non-science majors, using active learning techniques to engage the students. He will continue serving as SLP Co-Director.From a more technical perspective, the project will develop the idea that in QIS, temporal modes (TMs) of photons, and more generally light fields, should be viewed on an equal footing with polarization and transverse modes. TMs are wave-packet modes that have the same carrier frequency, polarization, and transverse spatial mode, and occupy the same time bin, but yet are temporal orthogonal. To enable the development of TMs for use as qubits and qudits, the central needed technology is the quantum pulse gate (QPG), which will implement a near-100% efficient spatial sorting of field-orthogonal TMs. Based on their recently proposed method of temporal-mode interferometry (TMI), the researchers will demonstrate the elements of a complete quantum information framework that employs field orthogonality of single-photon temporal modes. The three requirements - generation of resource states, the targeted and efficient manipulation of TMs, and their detection and characterization - can be fulfilled with current technology. In particular, the researchers will study, experimentally and theoretically, means for implementing single-qubit quantum-logic operations (Pauli-X, -Y, and -Z gates; and phase-shift gate) using the quantum pulse gate device as the basic building block. They will also demonstrate that the QPG can act as a real-time controllable switch that is temporal-mode selective, by varying a phase shift internal to the device. In addition, they will demonstrate means for verifying the fidelity of such gate operations, using a new form of quantum-state tomography, which can determine the quantum state directly in a TM basis.

量子信息科学（QIS）有望以传统（基于经典物理学）信息技术无法实现的方式存储、传输和处理信息。 QIS 的成功可以通过新的计算和通信能力彻底改变技术和科学。在这些成为现实之前，仍需要重大突破。人们普遍认为最强大的量子计算将使用材料系统（原子或电子）进行。相比之下，网络（“量子互联网”）上的量子通信将使用光（光子）进行。此外，根据需要，将使用光或光与相互作用原子的组合来进行专门的量子信息处理，例如，构建信号中继器，以将量子通信的范围扩展到更长的距离。该项目将开发一种激进但实用的新方法，使用光子对量子信息进行编码。光束中的光子具有四种不同的属性，其中任何一种属性都可用于编码量子信息：偏振（例如垂直或水平）、二维光束轮廓（空间形状）和时间形状（光脉冲期间亮度随时间的变化）。为了充分利用光在量子网络中传输信息，必须能够根据与这些特性相关的状态来操纵和分类光束。虽然偏振和空间光束轮廓先前已被开发为编码光子量子信息的手段，但光子的时间形状在很大程度上未被认为是一种重要的潜在技术。该项目致力于通过开发使用光子时间形状来编码信息的方法来完成基于光子的量子信息系统的“工具包”。这种方法的好处在于：1）它允许在单个光子上编码多于一位的信息，2）该编码方法对于在长光纤中传播时发生的光变化具有鲁棒性，3）该方法与基于原子的量子光存储器很好地接口，该存储器将用于未来构建量子互联网。 控制量子系统在科学和信息技术、计量学、量子化学和纳米力学领域引起了广泛的兴趣。光学技术和基于量子光学的信息科学为将研究与科学教育相结合提供了绝佳的机会。为了提高非科学专业的普通科学教育质量，P.I. 2010 年，他与人共同创立了俄勒冈大学科学素养项目 (SLP)，并担任其联合主任。 SLP 为许多研究生和科学专业本科生提供了指导性教学机会，担任科学素养课程的联合讲师。他开发并教授了 SLP 课程“所有人的量子物理学”，该课程向非科学专业的学生介绍量子信息科学，使用主动学习技术吸引学生。他将继续担任 SLP 联合主任。从更技术的角度来看，该项目将发展这样的想法：在 QIS 中，光子的时间模式 (TM) 以及更普遍的光场应该与偏振模式和横向模式同等看待。 TM 是波包模式，具有相同的载波频率、偏振和横向空间模式，并占据相同的时间仓，但时间正交。为了开发用作量子位和量子体的 TM，所需的核心技术是量子脉冲门 (QPG)，它将实现场正交 TM 近 100% 高效的空间排序。基于他们最近提出的时间模式干涉测量（TMI）方法，研究人员将展示采用单光子时间模式场正交性的完整量子信息框架的元素。当前的技术可以满足三个要求：资源状态的生成、TM 的有针对性和高效的操作以及它们的检测和表征。特别是，研究人员将通过实验和理论研究使用量子脉冲门器件作为基本构建块来实现单量子位量子逻辑运算（泡利-X、-Y和-Z门；以及相移门）的方法。他们还将证明 QPG 可以通过改变器件内部的相移来充当具有时间模式选择性的实时可控开关。此外，他们还将展示验证此类门操作保真度的方法，使用一种新形式的量子态断层扫描，可以直接在 TM 基础上确定量子态。