Purification to Locally Maximally Entangleable States

TL;DR

This paper introduces a new entanglement purification protocol for a broad class of multipartite states called LMESs with phases 0 or π, demonstrating improved performance over existing methods.

Contribution

It presents the first multipartite purification protocol tailored for LMESs with specific phases, incorporating a novel approach to handle their quantum correlations.

Findings

Purification protocol outperforms previous methods

Applicable to all LMESs with phases 0 or π

Demonstrates improved fidelity in multipartite entanglement

Abstract

Locally maximally entangleable states (LMESs) constitute a large set of multipartite states, containing for instance all stabilizer states. LMESs are uniquely characterized by (2n-1) phases, where n denotes the number of qubits. We consider here those LMES whose phases are either 0 or {\pi} and present a multipartite entanglement purification protocol for arbitrary such states. In contrast to all previously known recurrence protocols this protocol uses a novel ingredient, which is required due to the quantum correlations contained in the various LMESs. We compare this scheme to previously known entanglement purification protocols and show that the direct purification performs better than previously known protocols.