Information sharing in Quantum Complex Networks

TL;DR

This paper uses entanglement entropy to analyze information sharing in quantum complex networks, revealing that nodes with intermediate connectivity hold the most information, which helps determine network topology.

Contribution

It introduces entanglement entropy as a novel tool for studying information distribution in quantum networks and links mutual information to network topology.

Findings

Nodes with intermediate connectivity store the most information.

Mutual information characterizes the network topology.

External node information can reveal network structure.

Abstract

We introduce the use of entanglement entropy as a tool for studying the amount of information shared between the nodes of quantum complex networks. By considering the ground state of a network of coupled quantum harmonic oscillators, we compute the information that each node has on the rest of the system. We show that the nodes storing the largest amount of information are not the ones with the highest connectivity, but those with intermediate connectivity thus breaking down the usual hierarchical picture of classical networks. We show both numerically and analytically that the mutual information characterizes the network topology. As a byproduct, our results point out that the amount of information available for an external node connecting to a quantum network allows to determine the network topology.