论文标题
高斯纠缠见证人和完善连续变量的Werner-Wolf标准
Gaussian entanglement witness and refined Werner-Wolf criterion for continuous variables
论文作者
论文摘要
我们使用匹配的量子纠缠证人来研究连续变量状态的可分离标准。证人可以写为身份操作员，减去高斯操作员。然后，证人的优化转变为高斯内核积分方程的特征值问题。它不仅遵循了对称的高斯量子状态的可分离标准，而且还针对通过光子添加到OR和/和从对称高斯状态中减去的非高斯状态。基于Fock空间数字计算，我们获得了更通用的两种模式状态的纠缠见证人。两种模式状态的必要标准是可分离性的必要标准，对于两种模式挤压的热状态和相关的两模式非高斯状态来说，这是必要且足够的。我们还将基于证人的标准与Werner-Wolf标准联系起来，并完善Werner-Wolf标准。
We use matched quantum entanglement witnesses to study the separable criteria of continuous variable states. The witness can be written as an identity operator minus a Gaussian operator. The optimization of the witness then is transformed to an eigenvalue problem of a Gaussian kernel integral equation. It follows a separable criterion not only for symmetric Gaussian quantum states, but also for non-Gaussian states prepared by photon adding to or/and subtracting from symmetric Gaussian states. Based on Fock space numeric calculation, we obtain an entanglement witness for more general two-mode states. A necessary criterion of separability follows for two-mode states and it is shown to be necessary and sufficient for a two mode squeezed thermal state and the related two-mode non-Gaussian states. We also connect the witness based criterion with Werner-Wolf criterion and refine the Werner-Wolf criterion.
