Geometry of two-qubit states with negative conditional entropy
Quantum Physics
2017-02-23 v2
Abstract
We review the geometric features of negative conditional entropy and the properties of the conditional amplitude operator proposed by Cerf and Adami for two qubit states in comparison with entanglement and nonlocality of the states. We identify the region of negative conditional entropy in the tetrahedron of locally maximally mixed two-qubit states. Within this set of states, negative conditional entropy implies nonlocality and entanglement, but not vice versa, and we show that the Cerf-Adami conditional amplitude operator provides an entanglement witness equivalent to the Peres-Horodecki criterion. Outside of the tetrahedron this equivalence is generally not true.
Cite
@article{arxiv.1609.04144,
title = {Geometry of two-qubit states with negative conditional entropy},
author = {Nicolai Friis and Sridhar Bulusu and Reinhold A. Bertlmann},
journal= {arXiv preprint arXiv:1609.04144},
year = {2017}
}
Comments
16 pages, 6 figures, v2: minor updates to match published version