On Bell's Theorem, Quantum Communication, and Entanglement Detection
Abstract
(A) Bell's theorem rests on a conjunction of three assumptions: realism, locality and "free will." A discussion of these assumptions will be presented. It will be also shown that, if one adds to the assumptions the principle or rotational symmetry of physical laws, a stronger version of the theorem emerges. (B) A link between Bell's theorem and communication complexity problems will be presented. This also includes experimental realizations, which surprisingly do not involve entanglement. (C) A new sufficient and necessary criterion for entanglement of general (mixed) states will be presented. It is derived using the same geometric starting point as the inclusion of the symmetry in (A). The set of entanglement identifiers (EI's) emerging via this method contains entanglement witnesses (EW's), but they form only a subset of all EI's. Thus the method is more powerful than he one based on EW's.
- Publication:
-
Foundations of Probability and Physics - 5
- Pub Date:
- March 2009
- DOI:
- 10.1063/1.3109943
- arXiv:
- arXiv:0811.4142
- Bibcode:
- 2009AIPC.1101..208Z
- Keywords:
-
- 03.65.Ud;
- 03.65.Ta;
- 03.67.Hk;
- Entanglement and quantum nonlocality;
- Foundations of quantum mechanics;
- measurement theory;
- Quantum communication;
- Quantum Physics
- E-Print:
- 10 pages, for proceedings of Foundations of Probability and Physics-5 at Vaxjo University, Swedish Southeast Academy August 24-27, 2008