双量子比特置换不变态的矩阵表示及纠缠判据

摘要

讨论了翻转算子的部分性质,给出了双量子比特系统上置换不变态的具体矩阵表示,得到这类态上重排矩阵和偏转置矩阵之间的关系,即FρR=(ρTA)R,ρR F=(ρTB)R,其中,F表示翻转算子.最后通过矩阵元之间的关系式,给出了判断实置换不变态纠缠的一个量化判据.%In the paper,some relevant properties of swap operator are discussed,and the con-crete matrix representation for two-qubit permutationally invariant states is given.The correla-tion between realignment matrix and partial transpose matrix of these states is obtained.By the relations among entries of matrix,a quantitative criterion is given to judge whether or not two-qubit permutationally invariant states are entangled.