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  • Open Access

Spatio-spectral quantum networks in nonlinear photonic lattices

Natalia Costas1, Nadia Belabas2, and David Barral1,*

  • *Contact author: dbarral@cesga.es
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Phys. Rev. Research 7, 043320 – Published 22 December, 2025

DOI: https://doi.org/10.1103/bgls-md94

Abstract

Multiplexing information in different degrees of freedom is a natural solution to the scalability bottleneck in optical quantum communications and computing. However, for bulk-optics systems, size, cost, stability, and reliability can make scalability either impractical or highly challenging to implement. We present a framework to engineer continuous and discrete-variable entanglement produced through nondegenerate spontaneous parametric down-conversion in χ(2) nonlinear photonic lattices in spatial and spectral degrees of freedom that can alleviate the scalability challenge. We show how spatio-spectral pump shaping produces cluster states that are natively distributable in quantum communication networks and a resource for measurement-based quantum computing.

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Phys. Rev. Research 7, 043320– Published 22 December, 2025
  • Received 17 June 2025
  • Accepted 17 November 2025
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