激光与光电子学进展, 2019, 56 (18): 182701, 网络出版: 2019-09-09
准周期演化量子行走中的纠缠关联
Entanglement in Quasi-Periodic Evolution of Quantum Walks
摘要
研究了随相位位置变化的量子行走的性质,以及硬币和行走者之间的纠缠度。行走者回到原点的概率以及位置方差随演化时间呈准周期性变化,这种量子行走即为准周期演化量子行走。通过纠缠熵度量硬币和行走者之间的纠缠关联。数值计算表明纠缠熵与系统初态、演化步数以及相位因子有关。选择合适的硬币操作,纠缠熵随着演化步数呈现准周期性变化。对于给定的初态,选择适当的相位因子和演化步数,可使硬币与行走者处于最大纠缠态。
Abstract
We study the entanglement between the coin and walker in quantum walks which vary with phase position. The probability of returning to the position of the walker and the position variance vary with the evolution time quasi-periodically. Therefore, such quantum walks are called quasi-periodic evolutionary quantum walks. The coin-walker entanglement is measured by the von Neumann entropy of the coin. Through numerical calculations, we find that the entanglement entropy depends on the initial state, number of evolution steps, and phase factors. When the suitable coin operations are selected, the entanglement entropy changes in the quasi-period pattern. The maximum entanglement state can be obtained when the correct parameters of the evolution operator and number of evolution steps are selected for the given initial state.
张融, 刘文婷, 王杰, 郑培涛, 洪发. 准周期演化量子行走中的纠缠关联[J]. 激光与光电子学进展, 2019, 56(18): 182701. 张融, 刘文婷, 王杰, 郑培涛, 洪发. Entanglement in Quasi-Periodic Evolution of Quantum Walks[J]. Laser & Optoelectronics Progress, 2019, 56(18): 182701.