PIRSA:08120037

The impossibility of partially local hidden variable models for quantum theory and the relation to cryptography

Colbeck, R. (2008). The impossibility of partially local hidden variable models for quantum theory and the relation to cryptography. Perimeter Institute. https://pirsa.org/08120037

Colbeck, Roger. The impossibility of partially local hidden variable models for quantum theory and the relation to cryptography. Perimeter Institute, Dec. 12, 2008, https://pirsa.org/08120037 

          @misc{ pirsa_PIRSA:08120037,
            doi = {10.48660/08120037},
            url = {https://pirsa.org/08120037},
            author = {Colbeck, Roger},
            keywords = {Quantum Foundations},
            language = {en},
            title = {The impossibility of partially local hidden variable models for quantum theory and the relation to cryptography},
            publisher = {Perimeter Institute},
            year = {2008},
            month = {dec},
            note = {PIRSA:08120037 see, \url{https://pirsa.org}}
          }

Roger Colbeck University of York

DOI 10.48660/08120037
Collection
Talk Type Conference
Subject

Abstract

More than 40 years ago, Bell ruled out completely local hidden variable models as an explanation for quantum correlations. However, a new type of hidden variable model has recently been brought to light by the work of Leggett. Such a model has both local and non-local parts. Roughly speaking, having a local part means that the measurement outcomes can be guessed with better than 50% success. In this talk, I will explain that there exist quantum correlations for which any hidden variable model must have a trivial local part. I will then discuss how an extension of the original theorem implies that these correlations can be used to enhance the quality of a private random string.