Zhang Ming, Feng Lantian, Li Ming, Chen Yang, Zhang Long, He Deyong, Guo Guoping, Guo Guangcan, Ren Xifeng, Dai Daoxin
State Key Laboratory for Modern Optical Instrumentation, College of Optical Science and Engineering, Ningbo Research Institute, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China.
Key Laboratory of Quantum Information, CAS, University of Science and Technology of China, Hefei, Anhui 230026, China.
Phys Rev Lett. 2021 Apr 2;126(13):130501. doi: 10.1103/PhysRevLett.126.130501.
To build universal quantum computers, an essential step is to realize the so-called controlled-NOT (CNOT) gate. Quantum photonic integrated circuits are well recognized as an attractive technology offering great promise for achieving large-scale quantum information processing, due to the potential for high fidelity, high efficiency, and compact footprints. Here, we demonstrate a supercompact integrated quantum CNOT gate on silicon by using the concept of symmetry breaking of a six-channel waveguide superlattice. The present path-encoded quantum CNOT gate is implemented with a footprint of 4.8×4.45 μm^{2} (∼3λ×3λ) as well as a high-process fidelity of ∼0.925 and a low excess loss of <0.2 dB. The footprint is shrunk significantly by ∼10 000 times compared to those previous results based on dielectric waveguides. This offers the possibility of realizing practical large-scale quantum information processes and paving the way to the applications across fundamental science and quantum technologies.
要构建通用量子计算机，关键的一步是实现所谓的受控非门（CNOT门）。量子光子集成电路被公认为是一种极具吸引力的技术，因其具有实现高保真度、高效率和紧凑尺寸的潜力，为大规模量子信息处理带来了巨大希望。在此，我们利用六通道波导超晶格的对称性破缺概念，在硅基上展示了一种超紧凑集成量子CNOT门。目前这种路径编码的量子CNOT门的实现尺寸为4.8×4.45 μm²（约3λ×3λ），具有约0.925的高工艺保真度和小于0.2 dB的低额外损耗。与之前基于介质波导的结果相比，其尺寸显著缩小了约10000倍。这为实现实际的大规模量子信息处理提供了可能性，并为跨基础科学和量子技术的应用铺平了道路。
