Local equivalence of rank-2 quantum mixed states
Sergio A Albeverio, Shao-Ming Fei, Debashish Goswami · Journal of Physics A Mathematical and Theoretical · 2007
We investigate the equivalence of quantum mixed states under local unitary transformations. For a class of rank-2 mixed states, a sufficient and necessary condition of local equivalence is obtained by giving a complete set of invariants under local unitary transformations, such that two states in this class are locally equivalent if and only if all these invariants have equal values for them.