Group velocity difference effect on incoherent sum-frequency generation spectrum

Entanglement and nonlocality versus spontaneous emission in two-atom systems

“…Thus, for any initial state ρ, the concurrence C(ρ t ) approaches 0 when t → ∞. But still there can be some transient entanglement between atoms [9,10,11]. In this section we study in details time evolution of a given initial state ρ = (ρ jk ).…”

“…Note that our initial states are different from that considered in Ref. [11]. We study also the interesting problem how dissipative process of spontaneous emission influences nonlocal properties of initial states.…”

“…The idea that dissipation can create entanglement in physical systems, was recently developed in several papers [5,6,7,8]. In particular, the effect of spontaneous emission on destruction and production of entanglement in two -atom system was discussed [9,10,11]. Possible production of robust entanglement for closely separated atoms was shown in Ref.…”

“…Possible production of robust entanglement for closely separated atoms was shown in Ref. [9], and the existence of transient entanglement induced by this process in a system of two atoms separated by an arbitrary distance was also studied [10,11].…”

“…In this paper we also concentrate on arbitrarily separated atoms and consider the dynamics of entanglement. Similarly as in [11] we take some class of initial states, including interesting pure and mixed states, and discuss in details its time evolution as well as the evolution of its entanglement. Note that our initial states are different from that considered in Ref.…”