Remote Entanglement of Trapped Ions and Loophole-Free Bell Inequality

俘获离子的远程纠缠和无漏洞贝尔不等式

• 批准号: 1505326
• 负责人: Boris Blinov
• 金额: $ 47.5万
• 依托单位: University of Washington
• 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: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1505326&HistoricalAwards=false
• 关键词: Remote; Entanglement; Trapped; Ions; Loophole

The main goal of this project is to study quantum entanglement, which is arguably the most perplexing feature of the already confusing theory of quantum mechanics. Quantum mechanics, the theory that describes the microscopic world--elementary particles, atoms, molecules, photons and so on--allows particles to be at many places at the same time, a property called superposition. If several particles are in a superposition state, then their individual properties may become "entangled" in such a way that detecting one of the particles will affect the other particles even though there is no direct physical connection between them. Dubbed "spooky action at a distance" by Albert Einstein, this property has no classical physics analog, and its understanding is essential for verifying the validity of quantum mechanics. This seemingly esoteric property also has important practical applications and implications for a rapidly developing new technology: quantum computation and quantum communication. Quantum computers should be able to break computational speed records using exotic algorithms; their very existence requires strong quantum entanglement between the quantum bits, or "qubits", which form the basis of their operation. Quantum communication channels can transmit data with the highest possible levels of security; the reliability and range of these channels depends crucially on the ability to generate entanglement.The PI's will use trapped Ba ion qubits and the ion-photon entanglement protocol to generate long distance entanglement between the ions. The long (~1 km) range is needed to close both the locality loophole (which requires the measurements on the two qubits to be outside of each other's light cone) and the detection, or fair sampling, loophole (which requires that the detection efficiency is high) in the same experiment. The photons emitted by the ions will be sent though optical fibers and measured in a partial Bell state analyzer, a process which in turn entangles the distant ions via entanglement swapping.

该项目的主要目标是研究量子纠缠，这可以说是已经令人困惑的量子力学理论中最令人困惑的特征。量子力学是描述微观世界（基本粒子、原子、分子、光子等）的理论，它允许粒子同时存在于许多地方，这种性质称为叠加。如果多个粒子处于叠加状态，那么它们各自的属性可能会变得“纠缠”，即使它们之间没有直接的物理联系，检测其中一个粒子也会影响其他粒子。这一性质被阿尔伯特·爱因斯坦称为“幽灵般的超距作用”，没有经典物理学的类似物，它的理解对于验证量子力学的有效性至关重要。这种看似深奥的特性对于快速发展的新技术：量子计算和量子通信也具有重要的实际应用和影响。量子计算机应该能够使用奇特的算法打破计算速度记录；它们的存在需要量子位或“量子位”之间的强量子纠缠，这是其运行的基础。量子通信通道可以以尽可能高的安全级别传输数据；这些通道的可靠性和范围在很大程度上取决于产生纠缠的能力。PI 将使用捕获的 Ba 离子量子位和离子-光子纠缠协议来产生离子之间的长距离纠缠。在同一个实验中，需要长距离（~1公里）来弥补局域性漏洞（要求两个量子位的测量位于彼此的光锥之外）和检测或公平采样漏洞（要求检测效率高）。离子发射的光子将通过光纤发送，并在部分贝尔态分析仪中进行测量，这一过程又通过纠缠交换使远处的离子纠缠在一起。