Quantum Correlations In Assisted Optimal State Discrimination

There is a basic problem in quantum information is to explore different quantum correlation that play the roles in the process of quantum information. Recent research found by Roa. et al. [Phys. Rev. Lett., 107(2011) 080401] shows that, if there is a auxiliary system in assisted optimal state discrimination(AOSD), we can always find the protocol that entanglement is zero. At the same time, there is another kind of quantum correlation(Quantum dissonance) between systems. In other words, they showed, in assisted optimal state discrimination protocol, if we want to describe two nonorthogonal states with the same probability, quantum dissonance is the only quantum correlation required. The result has been extended to the multidimensional nonorthogonal states. On the other hand, the development of research work is to get achievement with arbitrary a priori probabilities. To this end, Zhang et al. [Sci. Rep., 3(2013) 2134] have improved the scheme and proved that the quantum entanglement of two quantum states in AOSD protocol is totally unnecessary. That is to say, compared with Quantum entanglement, Quantum dissonance in AOSD system has played a more important role. However, the original and extended work of state description just proves when the quantum states have the same probability, quantum entanglement can be zero. Through the improvement plan, we studied, is to distinguish a three-dimensional nonorthogonal states with a positive inner product. Our research found that three-dimensional quantum bit in AOSD quantum entanglement is completely unnecessary. At the same time, the results also show that quantum dissonance in general play a key role in optimal state discrimination assisted quantum information procedure.