Universal quantum gates play a critical role in quantum information processing. Here, based on the scattering property of photons off single emitters in one-dimensional waveguides, we present some heralded protocols for realizing controlled-not, Toffoli, and Fredkin gates on hybrid systems. The control qubit of our gates is encoded on a flying photon, and the target qubits are encoded in the degenerate ground states of the emitter. In our schemes, the faulty scattering processes between emitters and photons caused by system imperfections can be transformed into the detection of photon polarization. That is, our three quantum gates are accomplished in a heralded way. Moreover, the quantum circuits for the three gates are versatile and compact, and no additional qubits are required. With current technique on manipulating the emitter-waveguide system, our protocols may be experimentally feasible. This work provides an effective avenue for implementing quantum logic gates.

中文翻译：

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通过波导介导的光子散射为混合系统预示量子门

通用量子门在量子信息处理中发挥着关键作用。在这里，基于光子从一维波导中单个发射器的散射特性，我们提出了一些用于实现受控非、Toffoli 和 Fredkin 门在混合系统上。我们门的控制量子位在飞行光子上编码，目标量子位在发射器的简并基态中编码。在我们的方案中，由系统缺陷引起的发射器和光子之间的错误散射过程可以转化为光子极化的检测。也就是说，我们的三个量子门是以预兆的方式完成的。此外，三个门的量子电路通用且紧凑，不需要额外的量子位。使用目前操纵发射器波导系统的技术，我们的协议在实验上可能是可行的。这项工作为实现量子逻辑门提供了一种有效的途径。