Bell's Inequalities: Foundations and Quantum Communication - Quantum PhysicsReport as inadecuate

Bell's Inequalities: Foundations and Quantum Communication - Quantum Physics - Download this document for free, or read online. Document in PDF available to download.

Abstract: Efforts to construct deeper, realistic, level of physical description, inwhich individual systems have, like in classical physics, preexistingproperties revealed by measurements are known as hidden-variable programs.Demonstrations that a hidden-variable program necessarily requires outcomes ofcertain experiments to disagree with the predictions of quantum theory arecalled -no-go theorems-. The Bell theorem excludes local hidden variabletheories. The Kochen-Specker theorem excludes noncontextual hidden variabletheories. In local hidden-variable theories faster-that-light-influences areforbidden, thus the results for a given measurement actual, or justpotentially possible are independent of the settings of other measurementdevices which are at space-like separation. In noncontextual hidden-variabletheories the predetermined results of a degenerate observable are independentof any other observables that are measured jointly with it. It is a fundamentaldoctrine of quantum information science that quantum communication and quantumcomputation outperforms their classical counterparts. If this is to be true,some fundamental quantum characteristics must be behind better-than-classicalperformance of information processing tasks. This chapter aims at establishingconnections between certain quantum information protocols and foundationalissues in quantum theory. After a brief discusion of the most commonmisinterpretations of Bell-s theorem and a discussion of what its real meaningis, it will be demonstrated how quantum contextuality and violations of localrealism can be used as useful resources in quantum information applications.

Author: Caslav Brukner, Marek Zukowski


Related documents