Xue Peng, Qin Hao, Tang Bao
1] Department of Physics, Southeast University, Nanjing, Jiangsu 211189, China [2] State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China.
Department of Physics, Southeast University, Nanjing, Jiangsu 211189, China.
Sci Rep. 2014 Apr 28;4:4825. doi: 10.1038/srep04825.
Optical interferometers comprising birefringent-crystal beam displacers, wave plates, and phase shifters serve as stable devices for simulating quantum information processes such as heralded coined quantum walks. Quantum walks are important for quantum algorithms, universal quantum computing circuits, quantum transport in complex systems, and demonstrating intriguing nonlinear dynamical quantum phenomena. We introduce fully controllable polarization-independent phase shifters in optical pathes in order to realize site-dependent phase defects. The effectiveness of our interferometer is demonstrated through realizing single-photon quantum-walk dynamics in one dimension. By applying site-dependent phase defects, the translational symmetry of an ideal standard quantum walk is broken resulting in localization effect in a quantum walk architecture. The walk is realized for different site-dependent phase defects and coin settings, indicating the strength of localization signature depends on the level of phase due to site-dependent phase defects and coin settings and opening the way for the implementation of a quantum-walk-based algorithm.
由双折射晶体光束位移器、波片和移相器组成的光学干涉仪，是用于模拟诸如预告造币量子行走等量子信息过程的稳定装置。量子行走对于量子算法、通用量子计算电路、复杂系统中的量子输运以及展示有趣的非线性动力学量子现象都很重要。我们在光路中引入了完全可控的偏振无关移相器，以实现与位置相关的相位缺陷。通过在一维中实现单光子量子行走动力学，证明了我们干涉仪的有效性。通过应用与位置相关的相位缺陷，理想标准量子行走的平移对称性被打破，从而在量子行走架构中产生局域化效应。针对不同的与位置相关的相位缺陷和硬币设置实现了量子行走，这表明局域化特征的强度取决于由于与位置相关的相位缺陷和硬币设置而产生的相位水平，并为基于量子行走的算法的实现开辟了道路。
