English

Positive phase space transformation incompatible with classical physics

Quantum Physics 2009-04-08 v2

Abstract

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.

Keywords

Cite

@article{arxiv.0810.1457,
  title  = {Positive phase space transformation incompatible with classical physics},
  author = {Wonmin Son and Johannes Kofler and M. S. Kim and Vlatko Vedral and Caslav Brukner},
  journal= {arXiv preprint arXiv:0810.1457},
  year   = {2009}
}

Comments

4 pages, 1 figure, published version

R2 v1 2026-06-21T11:28:38.997Z