Channel discord and distortion

Zhang WW, Sanders YR, Sanders BC (2021)

Publication Type: Journal article

Publication year: 2021

Journal

New Journal of Physics Institute of Physics: Open Access Journals / Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft

Book Volume: 23

Journal Issue: 8

DOI: 10.1088/1367-2630/ac180a

Abstract

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.

Involved external institutions

Max-Planck-Institut für die Physik des Lichts (MPL) / Max Planck Institute for the Science of Light DE Germany (DE) University of Science and Technology of China (USTC) CN China (CN) Macquarie University AU Australia (AU)

How to cite

APA:

Zhang, W.-W., Sanders, Y.R., & Sanders, B.C. (2021). Channel discord and distortion. New Journal of Physics, 23(8). https://dx.doi.org/10.1088/1367-2630/ac180a

MLA:

Zhang, Wei-Wei, Yuval R. Sanders, and Barry C. Sanders. "Channel discord and distortion." New Journal of Physics 23.8 (2021).

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