Optimal purification of thermal graph states
Optimal purification of thermal graph states
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DOI：
10.1088/1367-2630/8/8/147
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发表时间：
2006-06
影响因子：
3.3
通讯作者：
A. Kay;J. Pachos;W. Dür;H. Briegel
中科院分区：
文献类型：
--
作者：
A. Kay;J. Pachos;W. Dür;H. Briegel
在本文中，提出了一种净化协议，并证明了当应用于受局部z噪声影响的图状态的特定子集时，其性能是最佳的。这样的混合状态可以通过使系统达到热平衡而产生，当它被描述为具有特定的图形状态作为其唯一基态的哈密顿量时。从这个方案中，我们得到了不可能提纯的临界温度Tcrit的确切值，以及相关的最佳纯化速率。提出了一种可能的图哈密顿量模拟方法，它只需要二部相互作用和局部磁场，就可以实现系统温度的调谐。
In this paper, a purification protocol is presented and its performance is proven to be optimal when applied to a particular subset of graph states that are subject to local Z-noise. Such mixed states can be produced by bringing a system into thermal equilibrium, when it is described by a Hamiltonian which has a particular graph state as its unique ground state. From this protocol, we derive the exact value of the critical temperature Tcrit above which purification is impossible, as well as the related optimal purification rates. A possible simulation of graph Hamiltonians is proposed, which requires only bipartite interactions and local magnetic fields, enabling the tuning of the system temperature.