Gao Zhanjie, Su Zengping, Song Qinghua, Genevet Patrice, Dorfman Konstantin E
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China.
Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
Nanophotonics. 2022 Nov 21;12(3):569-577. doi: 10.1515/nanoph-2022-0593. eCollection 2023 Feb.
Bell state measurement is vital to quantum information technology. Conventional linear optical elements, however, cannot fully distinguish all polarization Bell states without assisting of additional degrees of freedom. Leveraging on a pair of binary-pixel metasurfaces, we demonstrate direct measurement of all four polarization Bell states. Each metasurface is designed to produce two output modes that linearly superpose three Bell states in the coincidence counting measurement. By rotating the polarizers, the coincidence counting measurement achieves a tunable anticorrelation between one and the other two Bell states, achieving Bell state detection efficiency of 75% in a single measurement. Complete and deterministic Bell state measurement is further realized by performing two measurements. Our work shows the advantage of utilization of metasurfaces in quantum detection schemes and is of great applicative interest for quantum dense coding, entanglement swapping, quantum teleportation protocols, and novel quantum information processing tasks.
贝尔态测量对于量子信息技术至关重要。然而，传统的线性光学元件在没有额外自由度辅助的情况下，无法完全区分所有偏振贝尔态。利用一对二元像素超表面，我们展示了对所有四个偏振贝尔态的直接测量。每个超表面被设计为产生两个输出模式，在符合计数测量中线性叠加三个贝尔态。通过旋转偏振器，符合计数测量实现了一个贝尔态与另外两个贝尔态之间的可调反关联，在单次测量中实现了75%的贝尔态检测效率。通过进行两次测量进一步实现了完整且确定性的贝尔态测量。我们的工作展示了在量子检测方案中利用超表面的优势，对于量子密集编码、纠缠交换、量子隐形传态协议以及新型量子信息处理任务具有极大的应用价值。
