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arXiv · 2503.12276

Quantum-enhanced quickest change detection of transmission loss

Saikat Guha·Tiju Cherian John·Zihao Gong·Prithwish Basu
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Abstract

Augmenting a train of bright phase-modulated laser-light pulses of a coherent communications system with infinitesimally small quantum photons per pulse -- entangled across several time bins -- prepared by splitting squeezed light in a temporal-mode interferometer can dramatically enhance a homodyne receiver's ability to detect a sudden change in the channel loss, by up to a factor that is the inverse of the pre-change loss, without affecting the communications rate. We discuss the quantum limit of quickest change detection, and the problem of joint communications and change detection that our study opens up.

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Saikat Guha, Tiju Cherian John, Zihao Gong, Prithwish Basu. 2025-03-15. Quantum-enhanced quickest change detection of transmission loss. https://doi.org/10.1103/czg5-3y3d

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