Global control methods for Greenberger-Horne-Zeilinger-state generation on a one-dimensional Ising chain
Global control methods for Greenberger-Horne-Zeilinger-state generation on a one-dimensional Ising chain
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DOI：
10.1103/physreva.82.012330
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发表时间：
2010-04
影响因子：
2.9
通讯作者：
Xiaoting Wang;A. Bayat;S. Bose;S. Schirmer
中科院分区：
文献类型：
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作者：
Xiaoting Wang;A. Bayat;S. Bose;S. Schirmer
我们讨论了如何仅使用单个全局控制域制备GHZ状态下的Ising链。该模型不要求自旋是单独可寻址的，适用于量子系统，如光学晶格中的冷原子，一些液态或固态核磁共振实验，以及许多纳米级量子结构。我们证明了用绝热通道总是可以从某些容易制备的初始态渐近到达GHZ态，并且在一定条件下可以保证有限时间可达。为了给未来的实验实现提供参考，比较了实现目标\char22{}绝热通道的三种不同控制策略，Lyapunov控制和最优控制\char22{}，并讨论了它们的优缺点，特别是在存在不完全初始状态准备，系统非均匀性和减相等现实缺陷的情况下。
We discuss how to prepare an Ising chain in a GHZ state using a single global control field only. This model does not require the spins to be individually addressable and is applicable to quantum systems such as cold atoms in optical lattices, some liquid- or solid-state NMR experiments, and many nanoscale quantum structures. We show that GHZ states can always be reached asymptotically from certain easy-to-prepare initial states using adiabatic passage, and under certain conditions finite-time reachability can be ensured. To provide a reference useful for future experimental implementations, three different control strategies to achieve the objective\char22{}adiabatic passage, Lyapunov control, and optimal control\char22{}are compared, and their advantages and disadvantages discussed, in particular in the presence of realistic imperfections such as imperfect initial state preparation, system inhomogeneity, and dephasing.