Abstract:
Mutually unbiased measurements can be used to study the separability of quantum states. First, centered on the relationship between the diagonal symmetry states and the partial transpose positive of density matrix, combined with mutually unbiased measurements, the separability of two types of diagonal symmetric states in the bipartite quantum systems was studied, and the necessary and sufficient conditions for separability were obtained. Second, the separability of the quantum states in the bipartite quantum systems with 2-dimensional subsystems was studied. Using the Bloch representation of the density matrix and the relationship between the mutually unbiased measurements and the group generators, the necessary condition for separability was obtained. Finally, the separability of general quantum states in bipartite quantum systems was studied. By using the relationship between the trace norm and the vector norm, and the relationship between the mutually unbiased measurements and the density matrix, separability criteria for quantum states was presented. Moreover, this approach can detect more entangled states through some detailed examples.