Probing excited-state dynamics with quantum entangled photons: Correspondence to coherent multidimensional spectroscopy

TL;DR

This paper demonstrates how entangled photon pairs can be used for time-resolved spectroscopy, revealing system dynamics with high temporal resolution and spectral information through quantum correlations.

Contribution

It introduces a novel method of using frequency-entangled broadband photons for quantum-enhanced spectroscopy, linking quantum entanglement to multidimensional spectral analysis.

Findings

Temporal resolution of state-to-state dynamics via path difference adjustment

Spectral information along anti-diagonal lines in Fourier-transformed spectra

Potential for broader quantum light spectroscopy with engineered photon states

Abstract

Quantum light is a key resource for promoting quantum technology. One such class of technology aims to improve the precision of optical measurements using engineered quantum states of light. In this study, we investigate transmission measurement of frequency-entangled broadband photon pairs generated via parametric down-conversion with a monochromatic laser. It is observed that state-to-state dynamics in the system under study are temporally resolved by adjusting the path difference between the entangled twin beams when the entanglement time is sufficiently short. The non-classical photon correlation enables time-resolved spectroscopy with monochromatic pumping. It is further demonstrated that the signal corresponds to the spectral information along anti-diagonal lines of, for example, two-dimensional Fourier-transformed photon echo spectra. This correspondence inspires us to anticipate that more elaborately engineered photon states would broaden the availability of quantum light spectroscopy.