Strengthened Bell inequalities for entanglement verification
Strengthened Bell inequalities for entanglement verification
复制标题
用于纠缠验证的强化贝尔不等式
DOI：
10.1103/physreva.80.034302
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发表时间：
2009
影响因子：
2.9
通讯作者：
S. J. Enk
中科院分区：
文献类型：
--
作者：
P. Lougovski;S. J. Enk
贝尔不等式是用来测试量子力学与局部隐变量模型的，但也可以用来验证纠缠。为了纠缠验证的目的，人们假设量子力学的有效性以及测量的量子描述。在这些假设的帮助下，有可能得到一个加强的贝尔不等式，其违反意味着纠缠。我们推广已知的例子，这样的不平等有关的期望值的贝尔运营商的一个特定的量化措施的纠缠，即负性。此外，我们得到的统计数据说明了这样一个事实，即违反给定的（加强或不加强）贝尔不等式对于两个量子比特的量子态来说是一个比纠缠更罕见的壮举。
Bell inequalities were meant to test quantum mechanics vs local hidden variable models, but can also be used to verify entanglement. For entanglement verification purposes one assumes the validity of quantum mechanics as well as quantum descriptions of one's measurements. With the help of these assumptions it is possible to derive a strengthened Bell inequality whose violation implies entanglement. We generalize known examples of such inequalities by relating the expectation value of the Bell operator to a particular quantitative measure of entanglement, namely, the negativity. Moreover, we obtain statistics illustrating the fact that violating a given (strengthened or not) Bell inequality is a much more rare feat for a quantum state of two qubits than it is to be entangled.