Positive Phase Space Transformation Incompatible with Classical Physics

Author(s): W. Son, J. Kofler, M. S. Kim, V. Vedral, Č. Brukner

Journal: Physical Review Letters

Volume: 102

Page(s): 110404

Year: 2009

DOI Number: 10.1103/PhysRevLett.102.110404

Link: Link to publication


Bell conjectured that a positive Wigner function does not allow violation of the inequalities imposed by local

hidden variable theories. A requirement for this conjecture is ”when phase space measurements are performed”.

We introduce the theory-independent concept of ”operationally local transformations” which refers to the change

of the switch on a local measurement apparatus. We show that two separated parties, performing only phase space measurements on a composite quantum system with a positive Wigner function and performing only operationally local transformations that preserve this positivity, can nonetheless violate Bell’s inequality. Such operationally local transformations are realized using entangled ancillae.

Note: http://arxiv.org/abs/0810.1457

File: Link to PDF

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