Effect of long-range interactions on multipartite entanglement in Heisenberg chains

TL;DR

This paper investigates how long-range interactions in Heisenberg chains affect multipartite entanglement, revealing that increased interaction range does not necessarily lead to more global entanglement and depends on the system's phase structure.

Contribution

It provides new insights into the relationship between long-range interactions and multipartite entanglement in quantum spin chains, highlighting non-intuitive behaviors.

Findings

Multipartite entanglement can increase or decrease with interaction range.

Long-range interactions do not always enhance global entanglement.

Entanglement behavior reflects the phase structure of the system.

Abstract

It is well known that the notions of spatial locality are often lost in quantum systems with long-range interactions, as exhibited by the emergence of phases with exotic long-range order and faster propagation of quantum correlations. We demonstrate here that such induced ``quasinonlocal" effects do not necessarily translate to growth of global entanglement in the quantum system. By investigating the ground and quenched states of the variable-range, spin-1/2 Heisenberg Hamiltonian, we observe that the genuine multiparty entanglement in the system can either increase or counterintuitively diminish with a growing range of interactions. The behavior is reflective of the underlying phase structure of the quantum system and provides key insights for generation of multipartite entanglement in experimental atomic, molecular, and optical physics where such variable-range interactions have been implemented.