| The dissertation is devoted to local unitary invariants of quantum states under the Bloch representation.Combining coefficient matrices and the property about local unitary equivalence,we construct two pertinent sets.After that,according to the above sets,we structure sets about invariants.Because there are too many elements and indices,we need to determine the scope of the indices to control the number of elements to the minimum.During the research,what we study firstly is the invariants about three-qubit states.Then extending the result of invariants to the invariants about N-qubit states by similar methods.Next,we further research invariants of three-qutrit states.It is more complicated than bipartite states.We need to divide the system to construct the sets of the local unitary invariants,and to get the final results.At last,we generate the above results and arrive at the invariants of N-qutrit states. |
