Channel discord and distortion
Discord, originally notable as a signature of bipartite quantum correlation, in fact can be nonzero classically, i.e. arising from noisy measurements by one of the two parties. Here we redefine classical discord to quantify channel distortion, in contrast to the previous restriction of classical dis...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2021-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/ac180a |
| _version_ | 1827872657508401152 |
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| author | Wei-Wei Zhang Yuval R. Sanders Barry C. Sanders |
| author_facet | Wei-Wei Zhang Yuval R. Sanders Barry C. Sanders |
| author_sort | Wei-Wei Zhang |
| collection | DOAJ |
| description | Discord, originally notable as a signature of bipartite quantum correlation, in fact can be nonzero classically, i.e. arising from noisy measurements by one of the two parties. Here we redefine classical discord to quantify channel distortion, in contrast to the previous restriction of classical discord to a state, and we then show a monotonic relationship between classical (channel) discord and channel distortion. We show that classical discord is equivalent to (doubly stochastic) channel distortion by numerically discovering a monotonic relation between discord and total-variation distance for a bipartite protocol with one party having a noiseless channel and the other party having a noisy channel. Our numerical method includes randomly generating doubly stochastic matrices for noisy channels and averaging over a uniform measure of input messages. Connecting discord with distortion establishes discord as a signature of classical, not quantum, channel distortion. |
| first_indexed | 2024-03-12T16:26:56Z |
| format | Article |
| id | doaj.art-e570c92faa244d439a40a4d82bd32a55 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:26:56Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-e570c92faa244d439a40a4d82bd32a552023-08-08T15:41:40ZengIOP PublishingNew Journal of Physics1367-26302021-01-0123808302510.1088/1367-2630/ac180aChannel discord and distortionWei-Wei Zhang0https://orcid.org/0000-0002-8164-9527Yuval R. Sanders1https://orcid.org/0000-0001-8003-0039Barry C. Sanders2https://orcid.org/0000-0002-8326-8912Max Planck Institute for the Science of Light , Staudtstrae 2, 91058 Erlangen, Germany; Institute for Theoretical Physics II, Friedrich-Alexander-Universität Erlangen-Nürnberg , Staudtstrae 7, 91058 Erlangen, Germany; Centre for Engineered Quantum Systems, School of Physics, The University of Sydney , Sydney, AustraliaDepartment of Physics and Astronomy and ARC Centre of Excellence for Engineered Quantum Systems, Macquarie University , Sydney, AustraliaShanghai Branch, National Center for Physical Sciences at Microscale, University of Science and Technology of China , Shanghai 201315, People’s Republic of China; Institute for Quantum Science and Technology, University of Calgary , Alberta, T2N 1N4, CanadaDiscord, originally notable as a signature of bipartite quantum correlation, in fact can be nonzero classically, i.e. arising from noisy measurements by one of the two parties. Here we redefine classical discord to quantify channel distortion, in contrast to the previous restriction of classical discord to a state, and we then show a monotonic relationship between classical (channel) discord and channel distortion. We show that classical discord is equivalent to (doubly stochastic) channel distortion by numerically discovering a monotonic relation between discord and total-variation distance for a bipartite protocol with one party having a noiseless channel and the other party having a noisy channel. Our numerical method includes randomly generating doubly stochastic matrices for noisy channels and averaging over a uniform measure of input messages. Connecting discord with distortion establishes discord as a signature of classical, not quantum, channel distortion.https://doi.org/10.1088/1367-2630/ac180anoisy measurementstotal-variation distancedoubly stochastic channelchannel discordchannel distortion |
| spellingShingle | Wei-Wei Zhang Yuval R. Sanders Barry C. Sanders Channel discord and distortion New Journal of Physics noisy measurements total-variation distance doubly stochastic channel channel discord channel distortion |
| title | Channel discord and distortion |
| title_full | Channel discord and distortion |
| title_fullStr | Channel discord and distortion |
| title_full_unstemmed | Channel discord and distortion |
| title_short | Channel discord and distortion |
| title_sort | channel discord and distortion |
| topic | noisy measurements total-variation distance doubly stochastic channel channel discord channel distortion |
| url | https://doi.org/10.1088/1367-2630/ac180a |
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