Revivals of Bell nonlocality require Schr"odinger and Heisenberg non-Markovianity
The research investigates why Bell nonlocality can be restored over time in quantum systems. It finds that this revival requires memory effects, or non-Markovianity, in both the Schrödinger and Heisenberg pictures of dynamics. This joint non-Markovianity is essential for maintaining quantum resources like Bell nonlocality and enabling device-independent quantum key distribution.