Finite de Finetti theorem for infinite-dimensional systems.
Finite de Finetti theorem for infinite-dimensional systems.
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DOI：
10.1103/physrevlett.98.160406
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发表时间：
2006-06
影响因子：
8.6
通讯作者：
C. D'Cruz;T. Osborne;R. Schack
中科院分区：
文献类型：
--
作者：
C. D'Cruz;T. Osborne;R. Schack
我们制定并证明了一个de Finetti表示定理的可交换态的量子系统的k个无限维子系统。这个定理对于可以写成纯态的部分迹的状态是有效的|Psi/PSI|从n个子系统的全对称子空间的子集{Cn}族中选择。我们表明，这样的国家成为任意接近纯功率状态的混合物，n的增加。我们给出了族{Cn}的第二个等价刻画。
We formulate and prove a de Finetti representation theorem for finitely exchangeable states of a quantum system consisting of k infinite-dimensional subsystems. The theorem is valid for states that can be written as the partial trace of a pure state |Psi/Psi| chosen from a family of subsets {Cn} of the full symmetric subspace for n subsystems. We show that such states become arbitrarily close to mixtures of pure power states as n increases. We give a second equivalent characterization of the family {Cn}.