Coherence and quantum correlations measure sensitivity to dephasing channels

Journal Article · 16 January 2019 · Physical Review A

DOI: https://doi.org/10.1103/PhysRevA.99.012329 · OSTI ID:1492541

Yadin, Benjamin ^[1]; Bogaert, Pieter ^[1]; Susa, Cristian E. ^[2]; Girolami, Davide ^[3]

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1. Univ. of Oxford (United Kingdom)
2. Univ. de Cordoba, Monteria (Columbia); Univ. del Valle, Cali (Colombia)
3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

We introduce measures of quantum coherence as the speed of evolution of a system under decoherence. That is, coherence is the ability to estimate a dephasing channel, quantified by the quantum Fisher information. We extend the analysis to interferometric noise estimation, proving that quantum discord is the minimum sensitivity to local dephasing. A physically motivated set of free operations for discord is proposed. The amount of discord created by strictly incoherent operations is upper-bounded by the initial coherence.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: USDOE
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1492541
• Report Number(s): LA-UR-18-29513
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 1 Vol. 99; ISSN PLRAAN; ISSN 2469-9926
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English