Liu Qi, Tian Yu, Tian Zhaohua, Jia Yali, Li Guixin, Ren Xi-Feng, Gong Qihuang, Gu Ying
State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, Department of Physics, Peking University, Beijing, 100871, China.
Frontiers Science Center for Nano-optoelectronics & Collaborative Innovation Center of Quantum Matter & Beijing Academy of Quantum Information Sciences, Peking University, Beijing, 100871, China.
Light Sci Appl. 2025 May 13;14(1):193. doi: 10.1038/s41377-025-01871-5.
For the requirement of quantum photonic integration in on-chip quantum information, we propose a scheme to realize quantum controlled-Z (CZ) gates through single gradient metasurface. Using its parallel beam-splitting feature, i.e., a series of connected beamsplitters with the same splitting ratio, one metasurface can support a polarization encoding CZ gate or path encoding CZ gate, several independent CZ gates, and cascade CZ gates. Taking advantage that the path of output state is locked by the polarization of input state, path encoding CZ gates can efficiently filter out bit-flip errors coming from beam-splitting processes. These CZ gates also have the potential to detect quantum errors and generate high-dimensional entanglement through multi-degree-of-freedom correlation on metasurfaces. By integrating quantum CZ gates into a single metasurface, our results open an avenue for high-density and multifunctional integration of quantum devices.
针对片上量子信息中量子光子集成的需求，我们提出了一种通过单梯度超表面实现量子受控-Z（CZ）门的方案。利用其平行分束特性，即一系列具有相同分束比的相连分束器，一个超表面可以支持偏振编码CZ门或路径编码CZ门、多个独立的CZ门以及级联CZ门。利用输出态路径由输入态偏振锁定这一特性，路径编码CZ门可以有效滤除分束过程中产生的比特翻转错误。这些CZ门还具有检测量子错误并通过超表面上的多自由度关联产生高维纠缠的潜力。通过将量子CZ门集成到单个超表面中，我们的结果为量子器件的高密度和多功能集成开辟了一条途径。
