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Characterization of generalized coherent states through intensity-field correlations

Ignacio Salinas Valdivieso1,*, Victor Gondret2,*, Gerd Hartmann S.2, Mariano Uria3, Pablo Solano3, and Carla Hermann-Avigliano1,2,†,‡

  • *These authors contributed equally to this work.
  • †Contact author: carla.hermann@uchile.cl
  • ‡www.amazingquantum.com
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Phys. Rev. Research 8, 023118 – Published 4 May, 2026

DOI: https://doi.org/10.1103/lykp-833h

Abstract

Non-Gaussian quantum states of light are essential resources for quantum information processing and precision metrology. Among them, generalized coherent states (GCSs), which naturally arise from the evolution of a coherent state with a nonlinear medium, exhibit useful quantum features such as Wigner negativity and metrological advantages [Phys. Rev. Res. 5, 013165 (2023)]. Because these states remain coherent to all orders, their nonclassical character cannot be revealed through standard intensity-intensity correlation measurements. Here, we demonstrate that the intensity-field correlation function alone provides a simple and experimentally accessible witness of nonclassicality. For GCSs, any deviation of this normalized correlation from unity signals nonclassical behavior. We derive analytical results for Kerr-generated states and extend the analysis to statistical mixtures of GCSs. The proposed approach enables real-time, low-complexity detection of quantum signatures in non-Gaussian states, offering a practical tool for experiments across a broad range of nonlinear regimes.

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Phys. Rev. Research 8, 023118– Published 4 May, 2026
  • Received 17 December 2025
  • Accepted 25 March 2026
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