Determination of the maximum Global Quantum Discord via measurements of excitations in a cavity QED network

Multipartite Quantum Correlations is one of the most relevant indicator of the quantumness of a system in many body systems. This remarkable feature is in general difficult to characterize and the known definitions are hard to measure. Besides the efforts dedicated to solve this problem, the question of which is the best approach remains open. In this work, we study the Global Quantum Discord, GQD, as a bipartite and multipartite measure. We also check the limits of this definitions and present an experimental scheme to determine the maximum of the GQD via the measurements of the system's excitations, during the time evolution of the present system.