Entangled detectors nonperturbatively harvest mutual information

We investigate how entangled inertial Unruh-DeWitt detectors are affected by interaction with a quantum field using nonperturbative method. Inertial in ($3+1$)-dimensional Minkowski spacetime instantaneous switching ($\ensuremath{\delta}$-switching) experience degradation of their initial entanglement as coupling strength scalar increases. Somewhat surprisingly, initially separable or weakly can extract mutual information from the vacuum. also find that is not reduced if communication via possible; rather this only changes manner which degraded.