We investigate how nonlocal entanglement, as identified by violations of a Bell inequality, may be protected during the evolution. Our system consists of two qubits each embedded in a bosonic reservoir evolving independently and initially in an entangled mixed state. We show that the violation of the Bell inequality can be related to the single-qubit population of excited state in such a way that, by appropriately choosing structured environments that give rise to sufficiently high values of population trapping, long-time protection of nonlocal entanglement can be correspondingly achieved.
@article{arxiv.0810.2783,
title = {Long-time Protection of Nonlocal Entanglement},
author = {Bruno Bellomo and Rosario Lo Franco and Giuseppe Compagno},
journal= {arXiv preprint arXiv:0810.2783},
year = {2010}
}