End-to-end entanglement in Bose-Hubbard chains

TL;DR

This paper investigates how entanglement develops in Bose-Hubbard chains, revealing conditions for long-range entanglement and methods to enhance it through perturbations, with implications for quantum information processing.

Contribution

It demonstrates the emergence of long-range entanglement in Bose-Hubbard chains and proposes perturbations to enhance end-to-end entanglement beyond ground state levels.

Findings

Long-range entanglement arises from full-chain hopping.

Perturbations can increase end-site entanglement.

Ground state entanglement depends on hopping coefficients.

Abstract

We study the ground state as well as the dynamics of chains of bosons with local repulsive interactions and nearest-neighbour exchange using numerical techniques based on density matrix decimation. We explore the development of entanglement between the terminal sites of such chains as mechanisms are invoked to concentrate population in these sites. We find that long-range entanglement in the ground state emerges as a result of hopping taking place at the whole chain length in systems with appropriate hopping coefficients. Additionally, we find appropriate perturbations to increase the entanglement between the end sites above their ground state values.