Guo Yu, Liu Zixuan, Tang Hao, Hu Xiao-Min, Liu Bi-Heng, Huang Yun-Feng, Li Chuan-Feng, Guo Guang-Can, Chiribella Giulio
CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, 230026, China.
CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China.
Phys Rev Lett. 2024 Apr 19;132(16):160201. doi: 10.1103/PhysRevLett.132.160201.
Quantum theory allows information to flow through a single device in a coherent superposition of two opposite directions, resulting into situations where the input-output direction is indefinite. Here we introduce a theoretical method to witness input-output indefiniteness in a single quantum device, and we experimentally demonstrate it by constructing a photonic setup that exhibits input-output indefiniteness with a statistical significance exceeding 69 standard deviations. Our results provide a way to characterize input-output indefiniteness as a resource for quantum information and photonic quantum technologies and enable tabletop simulations of hypothetical scenarios exhibiting quantum indefiniteness in the direction of time.
量子理论允许信息以两个相反方向的相干叠加态在单个装置中流动，从而导致输入 - 输出方向不确定的情况。在此，我们引入一种理论方法来证明单个量子装置中的输入 - 输出不确定性，并通过构建一个光子装置进行实验演示，该装置表现出的输入 - 输出不确定性具有超过69个标准差的统计显著性。我们的结果提供了一种将输入 - 输出不确定性表征为量子信息和光子量子技术资源的方法，并能够对在时间方向上表现出量子不确定性的假设场景进行桌面模拟。
