Bounds on Quantum Correlations in Bell Inequality Experiments

摘要

The classification of mixed quantum states compatible with local-realistic description is both of fundamental importance and of great interest in quantum information processing. For a given Bell inequality, optimization of the corresponding Bell operator with respect to a given quantum state is a high-dimensional variational problem. In this talk, we present two algorithms that were developed to obtain, for a given quantum state, a lower bound and an upper bound on the maximal expectation value of a Bell operator. We will illustrate how these algorithms can be used to conclude definitively if some quantum states violate a given Bell inequality.