Entanglement sudden death with quasi-static approximation

In this paper, we investigate the entanglement sudden death with a two-level system and plasmonic surface. We determine the collective damping and qubit-qubit interaction by employing the quasi-static approximation. To illustrate this approach, we first derive the Markovian master equation in the Lindblad form using frequency-domain Green function approach. The Wootter's concurrence with Dicke states is used to measure the entanglement between two dipoles (two two-level systems). This approach enabled the present scheme to be applied in the field of quantum information theory.