Massively Scalable Quantum Entanglement and Quantum Processing in the Optical Frequency Comb

光频梳中的大规模可扩展量子纠缠和量子处理

• 批准号: 1206029
• 负责人: Olivier Pfister
• 金额: $ 54万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1206029&HistoricalAwards=false
• 关键词: Massively; Scalable; Quantum; Entanglement; Processing

Quantum computing promises exponential speedups over classical computing for specific but important tasks, such as data encryption and the simulation of quantum physics. However, the practical implementation of quantum computing faces daunting challenges: the need for scalability of "Qbit" (here, "Qmode") registers and the need to circumvent decoherence. This project from Prof. Pfister at the University of Virginia (UVa) aims at implementing large-scale entanglement in the periodic emission spectrum of an optical parametric oscillator (OPO), a.k.a. the "quantum optical frequency comb" (QOFC). It is based on the recent realization by Pfister's group of high-quality entanglement in a world-record 60 eigenmodes ("Qmodes") of the QOFC of a single OPO, into 15 sets of 4 Qmodes, each set being in a square cluster state. This successful experiment was the core of the project supported by an NSF award entitled "One-way quantum computing in the optical frequency comb." The objective of the current project is to build on this success and forge ahead toward highly scalable quantum information, along two lines of effort. On the one hand, we seek to generate record-size linear, square-grid, and cubic-lattice cluster states, which enable universal quantum computation. On the other hand, the group is striving to implement the quantum technologies needed for quantum processing in the QOFC. This includes: (i) developing low-loss, highly dispersive optical elements to separate Qmodes, (ii) implementing a network of balanced homodyne detection with high-efficiency PIN photodiodes using integrated optics, and (iii) performing high-efficiency nonGaussian measurements by way of photon-number-resolved detection, which has recently been implemented in Pfister's group at UVa thanks to a collaboration with Sae Woo Nam at NIST and Aaron Miller at Albion College, funded by an NSF MRI award entitled "Development of a photon-number-resolving detector system for universal quantum computing." This ambitious program is tantamount to creating a bona fide quantum computer over continuous variables, and studying quantum information in this context.The broader impacts of this work comprise an active research contribution to the UVa physics graduate and undergraduate programs. One recent undergraduate student was a former Goldwater Scholar who just joined the physics graduate program at Harvard, was a finalist of the 2011 LeRoy Apker Award of the American Physical Society, based on a paper he published with Prof. Pfister. Also stemming from this research, an advanced graduate course "Quantum Optics and Quantum Information" is now taught by the PI on a regular basis. On the interdisciplinary front, this research has spawned worldwide collaborative efforts. Finally, it is important to point out that quantum computing research has stakes in fundamental physics, as well as Defense and National Security: Shor's algorithm for factoring integers exponentially faster would defeat the widely-used RSA encryption protocol. Another direct application of a universal quantum processor of elementary size would be the modeling of presently intractable quantum problems in chemistry, materials science, and condensed-matter physics. Finally, the realization of a scalable quantum register offers possibilities for fundamental tests of quantum mechanics in the regime of mesoscopic entanglement and Schrödinger cats, where theoretical predictions become intractable. As quantum information comes of age, one can thus expect deeply significant scientific discoveries in all fields of the natural sciences.

量子计算有望在特定但重要的任务（例如数据加密和量子物理模拟）上实现比经典计算指数级的加速。然而，量子计算的实际实施面临着艰巨的挑战：对“Qbit”（此处为“Qmode”）的可扩展性的需求。 “）寄存器和规避退相干的需要。弗吉尼亚大学（UVa）Pfister 教授的这个项目旨在在光学参量振荡器的周期性发射光谱中实现大规模纠缠(OPO)，又名“量子光学频率梳”(QOFC) 它基于 Pfister 团队最近实现的单个 OPO QOFC 的世界纪录 60 个本征模（“Qmode”）的高质量纠缠。 ，分成 15 组 4 个 Qmode，每组都处于方形簇状态。这个成功的实验是该项目的核心，并获得了 NSF 奖项的支持。 “光学频率梳中的单向量子计算。”当前项目的目标是在这一成功的基础上，朝着高度可扩展的量子信息迈进，一方面，我们寻求创造记录。另一方面，该小组正在努力实现 QOFC 中量子处理所需的量子技术。低损耗、高色散光学元件来分离 Q 模式，(ii) 使用集成光学器件实现具有高效 PIN 光电二极管的平衡零差检测网络，以及 (iii) 通过光子数分辨检测来执行高效非高斯测量，该方法最近已在得益于与 NIST 的 Sae Woo Nam 和 Albion 学院的 Aaron Miller 的合作，该技术已在 UVa 的 Pfister 小组中得到实施，该项目由 NSF MRI 奖题为“发展用于通用量子计算的光子数分辨探测器系统。”这个雄心勃勃的计划相当于在连续变量上创建真正的量子计算机，并在这种背景下研究量子信息。这项工作的更广泛影响包括对以下方面的积极研究贡献：弗吉尼亚大学物理研究生和本科生项目的一名本科生是前金水学者，刚刚加入哈佛大学物理研究生项目，根据他与教授发表的一篇论文，入围了 2011 年美国物理学会 LeRoy Apker 奖的决赛。 。同样源于这项研究，PI 现在定期教授一门高级研究生课程“量子光学和量子信息”。在跨学科方面，这项研究催生了世界范围内的合作。量子计算研究与基础物理学以及国防和国家安全息息相关：Shor 的以指数速度分解整数的算法将击败广泛使用的 RSA 加密协议 基本尺寸通用量子处理器的另一个直接应用是。最后，可扩展量子寄存器的实现为介观纠缠和薛定谔猫领域中的量子力学的基本测试提供了可能性，其中理论预测成为可能。随着量子信息的成熟，人们可以期待在自然科学的所有领域中出现具有深远意义的科学发现。