Finite-time response function of uniformly accelerated entangled atoms
  We examine the transition probability from the ground state to a final entangled state of a system of uniformly accelerated two-level atoms weakly coupled with a massless scalar field in Minkowski vacuum. Using time-dependent perturbation theory we evaluate the finite-time response function and we identify the mutual influence of atoms via the quantum field as a coherence agent in each response function terms. The associated thermal spectrum perceived by the atoms is found for a finite time interval. By considering modifications of specific parameters of our setup, we also analyze how the transition probabilities are affected by the smoothness of the switching of the atom-field coupling. In addition, we study the mean life of the symmetric maximally entangled state for different accelerations. Our calculations reveal that smooth switching is more efficient than sudden switching concerning the reduction of the decay of the entangled state. The possible relevance of our results is discussed. 
C. D. Rodr\'iguez-Camargo, N. F. Svaiter and G. Menezes
quant-ph