Separability for mixed states with operator Schmidt rank two

Separability of Rank Two Quantum States

Explicit sufficient and necessary conditions for separability of higher dimensional quantum systems with rank two density matrices are given. A nonseparability inequality is also presented, for the case where one of the eigenvectors corresponding to nonzero eigenvalues is a maximally entangled state. PACS numbers: 03.65.Bz, 89.70.+c 1 SFB 256; SFB 237; BiBoS; CERFIM(Locarno); Acc. Arch.; USI(Me...

2 Schmidt numbers of low rank bipartite mixed states

Schmidt numbers of bipartite mixed states ([1]) characterize the minimum Schmidt ranks of pure states that are needed to construct such mixed states. It is the minimum number of degrees of freedom of a bipartite mixed state entangled between two parties. We give a lower bound of Schmidt numbers of low rank bipartite mixed states and conclude that generic (i.e., all outside a measure zero set) l...

Separability of rank two quantum states on multiple quantum spaces

Explicit sufficient and necessary conditions for separability of N-dimensional rank two multiparty quantum mixed states are presented. A nonseparability inequality is also given, for the case where one of the eigenvectors corresponding to nonzero eigenvalues of the density matrix is maximally entangled. PACS: 03.65.Bz;89.70.+c Quantum entanglement is playing an essential role in quantum informa...

All Unitaries Having Operator Schmidt Rank 2 are Controlled Unitaries

Separability of rank two quantum states on multiple quantum spaces with different dimensions

We consider the separability of rank two quantum states on multiple quantum spaces with different dimensions. The sufficient and necessary conditions for separability of these multiparty quantum states are explicitly presented. A nonseparability inequality is also given, for the case where one of the eigenvectors corresponding to nonzero eigenvalues of the density matrix is maximally entangled....