Integrated quantum photonic circuit is a promising platform for the realization of quantum information processing in the future. To achieve the large-scale quantum photonic circuits, the applied quantum logic gates should be as small as possible for the high-density integration on chips. Here, we report the implementation of super-compact universal quantum logic gates on silicon chips by the method of inverse design. In particular, the fabricated controlled-NOT gate and Hadamard gate are both nearly a vacuum wavelength, being the smallest optical quantum gates reported up to now. We further design the quantum circuit by cascading these fundamental gates to perform arbitrary quantum processing, where the corresponding size is about several orders smaller than that of previous quantum photonic circuits. Our study paves the way for the realization of large-scale quantum photonic chips with integrated sources and can have important applications in the field of quantum information processes.

中文翻译：

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具有逆向设计元素的超紧凑通用量子逻辑门

集成量子光子电路是未来实现量子信息处理的一个很有前途的平台。为实现大规模量子光子电路，所应用的量子逻辑门应尽可能小，以实现芯片上的高密度集成。在这里，我们报告了通过逆向设计的方法在硅芯片上实现超紧凑通用量子逻辑门。特别是，所制造的受控非门和阿达玛门都接近真空波长，是目前报道的最小的光量子门。我们通过级联这些基本门来进一步设计量子电路以执行任意量子处理，其中相应的尺寸比以前的量子光子电路小几个数量级。