Entanglement and Coherence: Differences and Similarities

Entanglement and coherence both decay due to environmental (heat bath) effects. Apart from the well-known fact that decoherence occurs exponentially and disentanglement occurs with a sudden death, there are many other differences. Here, we concentrate on the effects of temperature T along in the absence of dissipation. Thus, whereas the effect of T on decoherence increases exponentially with time [1], the effect of T on disentanglement is constant for all times [2], reflecting a fundamental difference between the two phenomena. Also, the possibility of disentanglement at a particular T increases with decreasing initial entanglement. Supported in part by NSF under Grant No. ECCS-0757204. \\[4pt] [1] G. W. Ford and R. F. O'Connell, Phys. Lett. A 286, 87 (2001). \\[0pt] [2] G. W. Ford and R. F. O'Connell, Phys. Scr. 82, 038112 (2010).