Implications of Disentanglement and Locality Induction for Quantum Information Processing

Entanglement and non-locality are global properties that depend on the coherence of quantum system states. These properties allow one to carry out communications and information processing tasks that are either impossible or far less efficient using only systems in classical physical states. However, even local environmental noise can degrade coherence and thereby degrade these quantum properties. Indeed, the phenomena of entanglement sudden death (ESD) and Bell non-locality sudden death (BNSD), which are defined as the falling to zero in finite time from a non-zero value of state entanglement and Bell inequality violation, respectively, can occur under such noise. Moreover, these processes can occur while state coherence itself still remains non-zero. Here, ESD is described and the threat it poses to quantum information processing is discussed.