Pulsed single-photon spectroscopy of an emitter with vibrational coupling

TL;DR

This paper analytically models how vibrational coupling affects the quantum state of single-photon scattering from a quantum emitter, revealing how vibrational effects influence quantum measurement precision in spectroscopy.

Contribution

It provides an analytical solution for the quantum state of scattered photons considering vibrational coupling, enabling new insights into vibrational effects in quantum light spectroscopy.

Findings

Vibration-induced dephasing reduces quantum Fisher information for linewidth estimation.

Frequency-resolved detection provides more information than time-resolved detection under strong vibrational coupling.

Vibrational effects can suppress light-matter interaction via Franck-Condon factors.

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.