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arXiv · 2512.14964

Pulsed single-photon spectroscopy of an emitter with vibrational coupling

Sourav Das·Aiman Khan·Elnaz Darsheshdar·Francesco Albarelli·Animesh Datta
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Abstract

We analytically derive the quantum state of a single-photon pulse scattered from a single quantum two-level emitter interacting with a vibrational bath. This solution for the quadripartite system enables an information-theoretic characterization of vibrational effects in quantum light spectroscopy. We show that vibration-induced dephasing reduces the quantum Fisher information (QFI) for estimating the emitter's linewidth, largely reflecting the Franck-Condon suppression of light-matter coupling. Comparing time- and frequency-resolved photodetection, we find the latter to be more informative in estimating the emitter's linewidth for stronger vibrational coupling.

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Sourav Das, Aiman Khan, Elnaz Darsheshdar, Francesco Albarelli, Animesh Datta. 2025-12-16. Pulsed single-photon spectroscopy of an emitter with vibrational coupling. https://arxiv.org/abs/2512.14964

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