Entangled Photons Enabled Time- and Frequency-Resolved Coherent Raman Spectroscopy in Condensed Phase Molecules

TL;DR

This paper introduces a novel ultrafast Raman spectroscopy technique using entangled photons to achieve simultaneous high temporal and spectral resolution in condensed phase molecules, revealing electronic and vibrational coherences.

Contribution

It develops a quantum correlation-based Raman spectroscopy method that surpasses classical limits, providing new insights into electronic coherence dynamics in molecules.

Findings

Electronic coherence decays within ~50 fs

Heterodyne detection captures phase information in real-time

Method achieves resolutions unattainable by classical pulses

Abstract

We develop an ultrafast frequency-resolved Raman spectroscopy with entangled photons for polyatomic molecules in condensed phases, to probe the electronic and vibrational coherences. Using quantum correlation between the photons, the signal shows the capability of both temporal and spectral resolutions that are not accessible by either classical pulses or the fields without entanglement. We develop a microscopic theory for this Raman spectroscopy, revealing the electronic coherence dynamics which often shows a rapid decay within $\sim$50fs. The heterodyne-detected Raman signal is further developed to capture the phases of electronic coherence and emission in real-time domain.