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Published on: November 11, 2013
Nonlocality distillation and postquantum theories with trivial communication complexity
Nicolas Brunner1, Paul Skrzypczyk
1H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, United Kingdom. n.brunner@bristol.ac.uk
Physical Review Letters
|June 13, 2009
Summary
We developed a protocol to distill quantum nonlocality, showing that certain nonlocal boxes, termed correlated nonlocal boxes, can be distilled to maximum nonlocality. These boxes, however, make communication complexity trivial, suggesting they may not exist in nature.
Area of Science:
- Quantum Information Theory
- Foundations of Quantum Mechanics
Background:
- Nonlocality is a key feature of quantum mechanics, distinguishing it from classical physics.
- Previous work established methods for distilling quantum correlations, but efficient protocols for specific nonlocal boxes were needed.
Purpose of the Study:
- To present an optimal protocol for deterministically distilling nonlocality for a specific class of quantum correlations.
- To investigate the implications of these distillable nonlocal boxes for communication complexity and their potential existence in nature.
Main Methods:
- Development of a two-copy distillation protocol based on prior work.
- Analysis of correlated nonlocal boxes and their asymptotic distillation.
- Application of established results on communication complexity to these boxes.
Main Results:
- The proposed protocol optimally distills nonlocality for correlated nonlocal boxes.
- In the asymptotic limit, all correlated nonlocal boxes distill to the Popescu-Rohrlich maximally nonlocal box.
- Correlated nonlocal boxes render communication complexity trivial, suggesting they are unlikely to exist physically.
Conclusions:
- The study provides a method for distilling quantum nonlocality and characterizes a class of nonlocal boxes.
- The findings suggest that the observed limits on quantum nonlocality might stem from the non-existence of certain types of nonlocal correlations.
- The research offers new insights into the boundary between quantum and classical correlations.
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