Sudden birth of maximal hidden quantum correlations.
Andrés F. Ducuara, Cristian E. Susa, John Henry Reina · arXiv (Cornell University) · 2020
We report on the existence of the phenomenon of sudden birth of maximal hidden quantum correlations in open quantum systems. Specifically, we consider the CHSH-inequality for Bell-nonlocality, the $\rm F_3$-inequality for EPR-steering, and usefulness for teleportation as quantum correlations in a bipartite qubit system under collective decoherence due to an environment. We show that, even though the system may undergo a sudden birth of entanglement, neither of the aforementioned correlations are present and yet, these can still be revealed by means of local filtering operations, thus evidencing the presence of hidden quantum correlations. Furthermore, there are extreme versions of this phenomenon for which the revealed correlations achieve their maximal amount allowed by quantum theory. The phenomenon of maximal hidden correlations relies on the qubits collective damping, and may take place even in long-distance separated qubits. These results prove that apparently-useless physical systems as quantum registers could still exhibit maximal correlations, which are hidden from us, but that can still be accessed by means of local filtering operations.