Reflected entropy is not a correlation measure
High Energy Physics - Theory
2023-06-08 v2 Quantum Physics
Abstract
By explicit counterexample, we show that the "reflected entropy" defined by Dutta and Faulkner is not monotonically decreasing under partial trace, and so is not a measure of physical correlations. In fact, our counterexamples show that none of the R\'enyi reflected entropies for is a correlation measure; the usual reflected entropy is realized as the member of this family. The counterexamples are given by quantum states that correspond to classical probability distributions, so reflected entropy fails to measure correlations even at the classical level.
Cite
@article{arxiv.2302.10208,
title = {Reflected entropy is not a correlation measure},
author = {Patrick Hayden and Marius Lemm and Jonathan Sorce},
journal= {arXiv preprint arXiv:2302.10208},
year = {2023}
}
Comments
v1 is 4 pages long; v2 contains light edits to bring the preprint in line with the published version, and is 4.5 pages long