Information Causality as a Physical Principle - Quantum PhysicsReport as inadecuate

Information Causality as a Physical Principle - Quantum Physics - Download this document for free, or read online. Document in PDF available to download.

Abstract: Quantum physics exhibits remarkable distinguishing characteristics. Forexample, it gives only probabilistic predictions non-determinism and does notallow copying of unknown state no-cloning. Quantum correlations may bestronger than any classical ones, nevertheless information cannot betransmitted faster than light no-signaling. However, all these features donot single out quantum physics. A broad class of theories exist which sharesuch traits with quantum mechanics, while they allow even stronger than quantumcorrelations. Here, we introduce the principle of Information Causality. Itstates that information that Bob can gain about a previously completely unknownto him data set of Alice, by using all his local resources which may becorrelated with her resources and a classical communication from her, isbounded by the information volume of the communication. In other words, ifAlice communicates m bits to Bob, the total information access that Bob gainsto her data is not greater than m. For m=0, Information Causality reduces tothe standard no-signaling principle. We show that this new principle isrespected both in classical and quantum physics, whereas it is violated by allthe no-signaling correlations which are stronger that the strongest quantumcorrelations. Maximally strong no-signalling correlations would allow Bobaccess to any m bit subset of the whole data set held by Alice. If only one bitis sent by Alice m=1, this is tantamount to Bob being able to access thevalue of any single bit of Alice-s data but of course not all of them. Wesuggest that Information Causality, a generalization of no-signaling, might beone of the foundational properties of Nature.

Author: M. Pawlowski, T. Paterek, D. Kaszlikowski, V. Scarani, A. Winter, M. Zukowski


Related documents