Contextuality with vanishing coherence and maximal robustness to dephasing

Abstract

Generalized contextuality is a resource for a wide range of communication and information processing protocols. However, contextuality is not possible without coherence, and so can be destroyed by dephasing noise. Here, we explore the robustness of contextuality to partially dephasing noise in a scenario related to state discrimination (for which contextuality is a resource). We find that a vanishing amount of coherence is sufficient to demonstrate the failure of noncontextuality in this scenario, and we give a proof of contextuality that is robust to arbitrary amounts of partially dephasing noise. This is in stark contrast to partially depolarizing noise, which is always sufficient to destroy contextuality.

12 pages, 7 figures. Comments are welcome!

References in corpus (8)

• Negativity and contextuality are equivalent notions of nonclassicality
• Preparation contextuality powers parity-oblivious multiplexing
• Set coherence: basis-independent quantification of quantum coherence
• Uniqueness of noncontextual models for stabilizer subtheories
• Contextual advantages and certification for maximum confidence discrimination
• Accessible fragments of generalized probabilistic theories, cone equivalence, and applications to witnessing nonclassicality
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• Experimental certification of contextuality, coherence and dimension in a programmable universal photonic processor
• Kirkwood-Dirac representations beyond quantum states (and their relation to noncontextuality)
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• Using a resource theoretic perspective to witness and engineer quantum generalized contextuality for prepare-and-measure scenarios
• Contextuality in anomalous heat flow
• No-broadcasting characterizes operational contextuality
• Contextuality witness inspired by optimal state discrimination
• Shadows and subsystems of generalized probabilistic theories: when tomographic incompleteness is not a loophole for contextuality proofs
• Constrained Measurement Incompatibility from Generalised Contextuality of Steered Preparation
• Robustness of contextuality under different types of noise as quantifiers for parity-oblivious multiplexing tasks
• Decoupling local classicality from classical explainability: A noncontextual model for bilocal classical theory and a locally-classical but contextual theory