Macroscopic Observables Detecting Genuine Multipartite Entanglement in Many Body Systems

Jing Yun Zhao, Hui Zhao, Naihuan Jing +1 more

Wen Xu, Zhu‐Jun Zheng, Chuan-Jie Zhu +1 more

A. Gabriel, Beatrix C. Hiesmayr

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.

Hui Zhao, Yu-Qiu Liu, Naihuan Jing +1 more

Sumit Nandi

Abstract In the present paper, a novel framework to detect genuine multipartite entanglement (GME) has been presented by computing correlations in mutually unbiased bases (MUBs). It has been shown that correlation obtained by measuring in MUBs of all biseparable multipartite states satisfy a bound, whereas GME states violate it. Thus, the presented framework turns out to be a sufficient criterion to detect entanglement in a many-body scenario. The methodology paves a suitable way to demonstrate certification of different classes of tripartite and quadripartite GME states. In addition to its operational universality, correlation obtained by measuring in MUBs is shown to be juxtaposed with some well-known genuine tripartite and quadripartite entanglement measures.

Géza Tóth, Otfried Gühne