Huelga SF, Macchiavello C, Pellizzari T, Ekert AK, Plenio MB, Cirac JI4 July 1997preprint Book Title:arXivNo abstract availableKeywords:5108 Quantum Physics , 5102 Atomic, Molecular and Optical Physics , 51 Physical Sciences , Bioengineering DOI10.48550/arxiv.quant-ph/9707014