2003/09/15 by Valerio Scarani, Scarani, Valerio
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.48550/arxiv.quant-ph/0309113
13 pages; Proceedings of the Workshop "Multiscale Methods in Quantum Mechanics", Rome, 16-20 December, 2002
arxiv created 2003/09/15 · arxiv updated 2009/12/01
This paper presents two unconventional links between quantum and classical physics. The first link appears in the study of quantum cryptography. In the presence of a spy, the quantum correlations shared by Alice and Bob are imperfect. One can either process the quantum information, recover perfect correlations and finally measure the quantum systems; or, one can perform the measurements first and then process the classical information. These two procedures tolerate exactly the same error rate for a wide class of attacks by the spy. The m second link is drawn between the quantum notions of "no-cloning theorem" and "weak-measurements with post-selection", and simple experiments using classical polarized light and ordinary telecom devices.