Distilling Nonlocality in Quantum Correlations

Abstract

Nonlocality, as established by seminal Bell's theorem, is considered to be the most striking feature of correlations present in space like separated events. Its practical application in device independent protocols, such as secure key distribution, randomness certification, {\it etc.}, demands identification and amplification of such correlations observed in the quantum world. In this Letter we study the prospect of nonlocality distillation, wherein, by applying a natural set of free operations (called wirings) on many copies of weakly nonlocal systems, one aims to generate correlations of higher nonlocal strength. In the simplest Bell scenario, we identify a protocol, namely, logical OR-AND wiring, that can distil nonlocality to significantly high degree starting from arbitrarily weak quantum nonlocal correlations. As it turns out, our protocol has several interesting facets: (i) it demonstrates that set of distillable quantum correlations has non zero measure in the full eight-dimensional correlation space, (ii) it can distil quantum Hardy correlations by preserving its structure, (iii) it shows that (nonlocal) quantum correlations sufficiently close to the local deterministic points can be distilled by a significant amount. Finally, we also demonstrate efficacy of the considered distillation protocol in detecting postquantum correlations.

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References in corpus (12)

• A convergent hierarchy of semidefinite programs characterizing the set of quantum correlations
• Device-independent quantum key distribution secure against collective attacks
• Bounding the set of quantum correlations
• Private Randomness Expansion With Untrusted Devices
• Non-locality distillation and post-quantum theories with trivial communication complexity
• Distilling Non-Locality
• Nonlocality and conflicting interest games
• Bound non-locality and activation
• Bounds for Non-Locality Distillation Protocols
• Self-testing quantum states via nonmaximal violation in Hardy's test of nonlocality
• Advantages of multi-copy nonlocality distillation and its application to minimizing communication complexity
• Nonlocality Distillation and Quantum Voids

Cited by in corpus (7)

• Quantum Nonlocality: Multi-copy Resource Inter-convertibility & Their Asymptotic Inequivalence
• Extending the Known Region of Nonlocal Boxes that Collapse Communication Complexity
• Scalable & Noise-Robust Communication Advantage of Multipartite Quantum Entanglement
• One-time Pad Encryption Model for Non-local Correlations
• Algebra of Nonlocal Boxes and the Collapse of Communication Complexity
• Device Independent Quantum Key Activation
• Suboptimality of Parity for Distilling Correlations with Nontrivial Marginals