论文标题
时间汤Qubt的受控遗相门的量子过程断层扫描
Quantum process tomography of a controlled-phase gate for time-bin qubits
论文作者
论文摘要
在不同时间在单个光子中编码信息的时量量子位已被广泛用于基于波导和波导的量子通信中。随着分布式量子计算的最新发展，逻辑询问时间键编码的量子位在这种情况下是否可能有用。我们最近使用基于尼贝特锂波导的2 x 2光学开关实现了一个时态量子Qubit控制的相（C相）门，我们证明了纠缠状态的产生。但是，仅用一对输入状态进行了实验，因此未完全验证C-相栅极的功能。在这项研究中，我们使用量子过程断层扫描来建立97.1％的过程保真度。此外，我们证明了受控门的运行，过程保真度大于94％。这项研究证实，可以用时间键量子台实现量子计算回路中使用的典型两级逻辑门，因此，这是实现基于时间键量子A的分布式量子计算的重要一步。
Time-bin qubits, where information is encoded in a single photon at different times, have been widely used in optical fiber and waveguide based quantum communications. With the recent developments in distributed quantum computation, it is logical to ask whether time-bin encoded qubits may be useful in that context. We have recently realized a time-bin qubit controlled-phase (C-Phase) gate using a 2 X 2 optical switch based on a lithium niobate waveguide, with which we demonstrated the generation of an entangled state. However, the experiment was performed with only a pair of input states, and thus the functionality of the C-Phase gate was not fully verified. In this research, we used quantum process tomography to establish a process fidelity of 97.1%. Furthermore, we demonstrated the controlled-NOT gate operation with a process fidelity greater than 94%. This study confirms that typical two-qubit logic gates used in quantum computational circuits can be implemented with time-bin qubits, and thus it is a significant step forward for realization of distributed quantum computation based on time-bin qubits.
