Du Yi-Mu, Lu Li-Hua, Li You-Quan
Department of Physics, Zhejiang University, Hangzhou, 310027, P. R. China.
Collaberative Innovation Center of Advanced Microstructure, Nanjing, P. R. China.
Sci Rep. 2018 May 8;8(1):7117. doi: 10.1038/s41598-018-25550-1.
The continuous-time quantum walk on a one-dimensional graph of odd number of sites with an on-site potential at the center is studied. We show that such a quantum-walk system can construct an X-gate of a single qubit as well as a control gate for two qubits, when the potential is much larger than the hopping strength. We investigate the decoherence effect and find that the coherence time can be enhanced by either increasing the number of sites on the graph or the ratio of the potential to the hopping strength, which is expected to motivate the design of the quantum gate with long coherence time. We also suggest several experimental proposals to realize such a system.
研究了在具有奇数个格点且中心存在在位势的一维图上的连续时间量子行走。我们表明，当势远大于跳跃强度时，这样的量子行走系统可以构造单比特的X门以及双比特的控制门。我们研究了退相干效应，发现通过增加图上的格点数或势与跳跃强度的比值，可以提高相干时间，这有望推动长相干时间量子门的设计。我们还提出了几个实现这种系统的实验方案。
