Macroscopic Observables Detecting Genuine Multipartite Entanglement and Partial Inseparability in Many-Body Systems

TL;DR

This paper introduces a method to detect genuine multipartite entanglement in many-body systems using only macroscopic observables like energy, enabling identification of entanglement properties relevant for quantum information applications.

Contribution

The authors develop criteria based on the GME gap and k-entanglement gap that detect large regions of entanglement not identified by existing methods.

Findings

The criteria effectively detect genuine multipartite entanglement in many-body states.

The methods outperform previous criteria in identifying entanglement regions.

Applicable to condensed matter systems for quantum information tasks.

Abstract

We show a general approach for detecting genuine multipartite entanglement (GME) and partial inseparability in many-body-systems by means of macroscopic observables (such as the energy) only. We show that the obtained criteria, the "GME gap" and "the k-entanglement gap", detect large areas of genuine multipartite entanglement and partial entanglement in typical many body states, which are not detected by other criteria. As genuine multipartite entanglement is a necessary property for several quantum information theoretic applications such as e.g. secret sharing or certain kinds of quantum computation, our methods can be used to select or design appropriate condensed matter systems.