Extracting perfect GHZ states from imperfect weighted graph states via entanglement concentration

TL;DR

This paper introduces an entanglement concentration protocol that transforms imperfect weighted graph states into perfect GHZ states using local operations, addressing key challenges in scalable quantum state generation.

Contribution

The authors propose a novel, efficient entanglement concentration method that produces perfect GHZ states from imperfect states with robustness to noise, advancing quantum information applications.

Findings

Protocol successfully generates high-fidelity GHZ states

Robustness demonstrated against incoherent noise

Efficient use of local gates and measurements

Abstract

Photonic GHZ states serve as the central resource for a number of important applications in quantum information science, including secret sharing, sensing, and fusion-based quantum computing. The use of photon-emitter entangling gates is a promising approach to creating these states that sidesteps many of the difficulties associated with intrinsically probabilistic methods based on linear optics. However, the efficient creation of high-fidelity GHZ states of many photons remains an outstanding challenge due to both coherent and incoherent errors during the generation process. Here, we propose an entanglement concentration protocol that is capable of generating perfect GHZ states using only local gates and measurements on imperfect weighted graph states. We show that our protocol is both efficient and robust to incoherent noise errors.