中文摘要：

讨论了熵相等的量子态和量子态的酉等价之间的关系,证明了任意两个满足受控关系的量子态ρ,σ,量子熵相等的充分必要条件是存在某个酉算子U使得ρ=UσU＊。并从另一角度建立2维情况下的等价关系。最后对一个关于量子熵的结果进行改进。

英文摘要：

Two unitarily equivalent quantum states have the same Von Neumann entropy,but not vice versa.In this paper a sufficient and necessary condition of unitary equivalence of quantum states associated with the Von Neumann entropy is given. Moreover,we extend a result of Von Neumann entropy by the theory of majorization.