Quantum-Enhanced Sensing of Excited-State Dynamics with Correlated Photons

TL;DR

This paper demonstrates how quantum-correlated squeezed photons enhance transient absorption spectroscopy, enabling real-time, high-resolution monitoring of excited-state dynamics in materials like TMDs, surpassing conventional methods.

Contribution

It introduces a microscopic theory for using tailored squeezed photons in transient absorption, revealing a novel time-energy-resolved sensing capability for studying nonequilibrium matter dynamics.

Findings

Achieved real-time monitoring of valley excitons in TMDs.

Developed a microscopic theory for quantum-enhanced transient absorption.

Identified intermediate squeezing as optimal for time-resolved spectroscopy.

Abstract

The squeezed photons, as a quantum-correlated light with reduced noise, have emerged as a great resource for sensing the structures of matter. Here we study the transient absorption (TA) scheme using the squeezed photons whose spectral correlation of amplitudes can be tailored. A microscopic theory is developed, revealing a highly time-energy-resolved nature of the signal that is not attainable by conventional TA scheme. Such a capability is elaborated by applying to monolayer transition metal dichalcogenide materials (TMDs), achieving a real-time monitoring of valley excitons and their dynamics. Moreover, we show the intermediate squeezing regime-not the strong squeezing-which the time-resolved spectroscopy is in favor of. Our work offers a new paradigm for studying nonequilibrium dynamics of matter, in light of the photocatalysis and optoelectronics.