基于开放量子行走的纠缠态制备协议
State Preparation Protocols for Entangled States via Open Quantum Walks
中文总结 AI 辅助
本研究基于开放量子行走（OQW）结构，构建了可制备Dicke态、GHZ态等纠缠态的协议，推导了环形OQW的谱隙闭式近似，分析了非尖锐测量的影响，并证明量子轨迹方法可嵌入OQW框架。
中文摘要 AI 辅助
开放量子行走（OQW）将图上的跃迁与内部自由度的量子操作耦合，我们利用该结构制定具有非幺正Kraus算符的量子态制备协议。我们构建了环形OQW以制备Dicke态系综，其中W态作为单激发情形出现，通过后选择行走者位置可恢复任意单个Dicke态；其收敛性由底层马尔可夫链的谱隙决定，我们得到了该谱隙的闭式近似表达式。对于GHZ态，我们提出一种双节点协议，其使用由投影测量构建的Kraus算符，可确定性地制备GHZ态而无需测量行走者，并分析了非尖锐测量对结果及行走收敛性的影响。我们还证明量子轨迹方法作为图结构碰撞模型自然嵌入OQW框架中。
英文摘要
Open quantum walks couple transitions on a graph to quantum operations on an internal degree of freedom. We use this structure to formulate protocols for quantum state preparation with nonunitary Kraus operators. We construct a ring-shaped OQW preparing an ensemble of Dicke states, with W states appearing as the single-excitation case, from which any individual Dicke state is recovered by postselecting the walker position; its convergence is governed by the spectral gap of the underlying Markov chain, for which we obtain a closed-form approximate expression. For GHZ states we present a two-node protocol using Kraus operators built from projective measurements that prepares them deterministically without requiring a measurement of the walker, and analyze how unsharp measurements affect the results and the convergence of the walk. We also show that the quantum trajectories method embeds naturally in the OQW framework as a graph-structured collision model.
