Gaussian geometric discord
Abstract
We extend the geometric measure of quantum discord, introduced and computed for two-qubit states in [B. Dakic, C. Brukner, and V. Vedral, Phys. Rev. Lett. 105, 190502 (2010)], to quantify non-classical correlations in composite Gaussian states of continuous variable systems. We lay the formalism for the evaluation of a Gaussian geometric discord in two-mode Gaussian states, and present explicit formulas for the class of two-mode squeezed thermal states. In such a case, under physical constraints of bounded mean energy, geometric discord is shown to admit upper and lower bounds for a fixed value of the conventional (entropic) quantum discord. We finally discuss alternative geometric approaches to quantify Gaussian quadrature correlations.
Cite
@article{arxiv.1110.2532,
title = {Gaussian geometric discord},
author = {Gerardo Adesso and Davide Girolami},
journal= {arXiv preprint arXiv:1110.2532},
year = {2011}
}
Comments
13 pages, 2 figures. To appear in IJQI Special Issue on Quantum Correlations: Entanglement and beyond