Spectrally Robust Photon-Pair Generation in Topological Waveguide Arrays
Abstract
Harnessing topological effects offers a route to protect quantum states of light from imperfections, potentially enabling more robust platforms for quantum information processing. This capability is particularly relevant for active photonic circuits that generate quantum light directly on-chip. However, the impact of topology on the spectral properties of parametric processes, crucial for scalable quantum photonic circuits, remains largely unexplored. Here, we address this question by investigating photon-pair generation via spontaneous parametric down-conversion (SPDC) in nonlinear waveguide arrays, combining experiment and theory. A systematic comparison of uniform, trivial, and topological Su-Schrieffer-Heeger (SSH) arrays reveals that only the topological configuration preserves a stable SPDC resonance spectrum under coupling disorder, with fluctuations in the resonance wavelength reduced by more than an order of magnitude. An analytical model captures the origin of this robustness in the band-structure properties of the interacting modes. Numerical analysis further shows that each SSH array can operate as a robust photon-pair source, enabling stable interference between multiple such sources and the generation of high-dimensional entangled states with high fidelity. These results establish nonlinear waveguide arrays as a promising platform for harnessing the interplay of topology and nonlinearity in quantum photonic circuits.
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BibTeX
@article{zecchetto2026spectrally,
title = {{Spectrally Robust Photon-Pair Generation in Topological Waveguide Arrays}},
author = {A. Zecchetto and J. -R. Coudevylle and M. Morassi and A. Lemaître and M. I. Amanti and S. Ducci and F. Baboux},
journal = {PRX Quantum},
year = {2026},
month = oct,
doi = {10.1103/kszt-p63d},
eprint = {2510.23796},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05797799v1},
note = {CC BY},
}
RIS
TY - JOUR
TI - Spectrally Robust Photon-Pair Generation in Topological Waveguide Arrays
AU - A. Zecchetto
AU - J. -R. Coudevylle
AU - M. Morassi
AU - A. Lemaître
AU - M. I. Amanti
AU - S. Ducci
AU - F. Baboux
PY - 2026
DA - 2026/10/13
JO - PRX Quantum
DO - 10.1103/kszt-p63d
UR - https://hal.science/hal-05797799v1
AB - Harnessing topological effects offers a route to protect quantum states of light from imperfections, potentially enabling more robust platforms for quantum information processing. This capability is particularly relevant for active photonic circuits that generate quantum light directly on-chip. However, the impact of topology on the spectral properties of parametric processes, crucial for scalable quantum photonic circuits, remains largely unexplored. Here, we address this question by investigating photon-pair generation via spontaneous parametric down-conversion (SPDC) in nonlinear waveguide arrays, combining experiment and theory. A systematic comparison of uniform, trivial, and topological Su-Schrieffer-Heeger (SSH) arrays reveals that only the topological configuration preserves a stable SPDC resonance spectrum under coupling disorder, with fluctuations in the resonance wavelength reduced by more than an order of magnitude. An analytical model captures the origin of this robustness in the band-structure properties of the interacting modes. Numerical analysis further shows that each SSH array can operate as a robust photon-pair source, enabling stable interference between multiple such sources and the generation of high-dimensional entangled states with high fidelity. These results establish nonlinear waveguide arrays as a promising platform for harnessing the interplay of topology and nonlinearity in quantum photonic circuits.
SN - 2691-3399
ER -