不可扩张纠缠基在系统粗化后的扩张性

Extension of the Unextendible Entangled Basis Under Coarsening the System

针对三体系统C^(d)_(1)■C^(4)■C^(d)_(2)中的特殊Schmidt 2秩不可扩张纠缠基(SUEB2),判断了其在系统粗化后的扩张性.首先构造了C d C^(4)■中的SUEB2,运用由m体构造m+1体系统中UEB k的方法,又构造了C^(d)_(1)■C^(4)■C^(d)_(2)中的SUEB2.发现C^(d)_(1)■C^(4)■C^(d)_(2)中的SUEB2在系统粗化后不全是SUEB2s,对于系统粗化后不是SUEB2s的向量通过增加向量得到了SUEB2s,且和文献中的SUEB2s是不等价的.

The extension of special unextendible entangled basis with Schmidt number 2(SUEB2)in three-partite system C^(d)_(1)■C^(4)■C^(d)_(2) under coarsening subsystems is discussed.Firstly,SUEB2 in C d C^(4)■ are constructed,and then SUEB2 in C^(d)_(1)■C^(4)■C^(d)_(2) is constructed by using method of constructing(m+1)-partite UEB k from m-partite.It is found that SUEB2s in C^(d)_(1)■C^(4)■C^(d)_(2) are not all SUEB2s after system coarsening,SUEB2s can be obtained by adding vectors for vectors that are not SUEB2s after system coarsening,and they are not equivalent to SUEB2s in the literature.