Heralded universal quantum gates can largely decrease the quantum resource consumed in the integration of a multiqubit quantum circuit. Here, we present a scheme for heralded universal quantum computing, including the construction of the CNOT gate, Fredkin gate, and Toffoli gate on the electron spins in diamond nitrogen-vacancy (NV) centers assisted by low-$ Q $ microtoroidal resonators. These quantum gates can achieve unity fidelity, as the infidelity induced by the imperfect input–output process is transferred into photon loss. The clicks on different single-photon detectors can either herald the success of the quantum gates or instruct an immediate recycling procedure, even without reinitializing the NV centers. Besides the heralding, this scheme is also more realistic, observing that the non-monochromatic auxiliary photon and the inhomogeneous NV centers have no adverse impact on fidelity. The high fidelity and efficiency with experimental parameters show that the scheme is feasible with current technology.

中文翻译：

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低Q微环形谐振器辅助金刚石氮空位中心电子自旋的先驱性通用量子计算

公开的通用量子门可大大减少多量子位量子电路集成中消耗的量子资源。在这里，我们提出了一种预示性通用量子计算的方案，包括在低氮Q（Q）辅助下在金刚石氮空位（NV）中心的电子自旋上构造CNOT门，Fredkin门和Toffoli门。微环形谐振器。这些量子门可以实现统一的保真度，因为不完美的输入输出过程引起的保真度会转化为光子损失。即使不重新初始化NV中心，点击不同的单光子探测器也可以预示量子门的成功或指示立即进行回收程序。除了预示之外，该方案还更加实际，可以观察到非单色辅助光子和非均匀NV中心对保真度没有不利影响。实验参数的高保真度和高效率表明该方案在当前技术下是可行的。