Entanglement and non-Gaussianity are physical resources that are essential for a large number of quantum-optics protocols. Non-Gaussian entanglement is indispensable for quantum-computing advantage and outperforms its Gaussian counterparts in a number of quantum-information protocols. The characterization of non-Gaussian entanglement is a critical matter as it is in general highly demanding in terms of resources. We propose a simple protocol based on the Fisher information for witnessing entanglement in an important class of non-Gaussian entangled states: photon-subtracted states. We demonstrate that our protocol is relevant for the detection of non-Gaussian entanglement generated by multiple photon-subtraction and that it is experimentally feasible through homodyne detection.
@article{arxiv.2301.03909,
title = {Metrological detection of entanglement generated by non-Gaussian operations},
author = {David Barral and Mathieu Isoard and Giacomo Sorelli and Manuel Gessner and Nicolas Treps and Mattia Walschaers},
journal= {arXiv preprint arXiv:2301.03909},
year = {2024}
}
Comments
We have corrected errors found in Figures 8 and 9 of the previous version and improved the manuscript with an analysis of the entanglement produced by multi-photon subtraction. We have adapted the main text, abstract and title correspondingly. 16 pages, 14 figures