Contextuality From a Quantum Information-Theoretic Perspective

SPEAKER: Dr. Robert Spekkens, University of CambridgeAbstract: Quantum theory is contextual in the sense that it does not admit a noncontextual hidden variable model, as demonstrated by the Bell-Kochen-Specker theorem. It is interesting to speculate that contextuality might be responsible for certain quantum improvements in information processing tasks, such as, for instance, random access codes and computational speed-ups. As a precursor to such an investigation, it is useful to reconsider the definition of contextuality from a modern quantum information theoretic perspective. I argue that such a perspective leads one naturally to a generalization of the standard notion of contextuality. Using this new definition, one can prove that quantum theory is contextual for preparations, transformations, and unsharp measurements. The possible significance of these results to quantum information theory will be discussed.Bio: Robert Spekkens did his undergraduate degree in Physics at McGill University, and his graduate work was done at the University of Toronto. He was a postdoc at Perimeter Institute for 3 years. Since Jan. 2006, He has been taking up a Royal Society fellowship at the University of Cambridge. Half of his time is spent on quantum information theory and the other half on quantum foundations.Host: Todd Brun, tbrun@usc.edu

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Mayumi Thrasher