论文标题
纠缠的对称状态和共同矩阵
Entangled symmetric states and copositive matrices
论文作者
论文摘要
对称量子状态的纠缠和共同矩阵的理论是密切相关的概念。对于最简单的对称状态,即对角线对称(DS)状态,已经证明存在异常(非远外)共同矩阵与不可解释(可分解(可分解的)纠缠见证人(EWS)之间存在对应关系。在这里,我们表明,对称的EWS(而不是DS)也可以从扩展的同构矩阵中构造,从而在任意奇数维度中提供了结合纠缠的对称状态的新示例,以及其相应的EWS。
Entanglement in symmetric quantum states and the theory of copositive matrices are intimately related concepts. For the simplest symmetric states, i.e., the diagonal symmetric (DS) states, it has been shown that there exists a correspondence between exceptional (non-exceptional) copositive matrices and non-decomposable (decomposable) Entanglement Witnesses (EWs). Here we show that EWs of symmetric, but not DS, states can also be constructed from extended copositive matrices, providing new examples of bound entangled symmetric states, together with their corresponding EWs, in arbitrary odd dimensions.