Core-hole Coherent Spectroscopy in Molecules

TL;DR

This paper investigates ultrafast core-excited state dynamics in nitrous oxide, demonstrating that quantum beatings persist longer than decoherence effects, and proposes a novel experimental approach using X-ray free-electron lasers.

Contribution

It provides a detailed theoretical analysis of core-hole coherence dynamics and introduces a new experimental scheme for observing these ultrafast processes.

Findings

Decoherence is slower than quantum beatings, allowing multiple oscillations.

High-level ab-initio methods effectively model core-excited state dynamics.

Proposed experiment can trace coherence evolution with X-ray free-electron lasers.

Abstract

We study the ultrafast dynamics initiated by a coherent superposition of core-excited states of nitrous oxide molecule. Using high-level \textit{ab-initio} methods, we show that the decoherence caused by the electronic decay and the nuclear dynamics is substantially slower than the induced ultrafast quantum beatings, allowing the system to undergo several oscillations before it dephases. We propose a proof-of-concept experiment using the harmonic up-conversion scheme available at X-ray free-electron laser facilities to trace the evolution of the created core-excited-state coherence through a time-resolved X-ray photoelectron spectroscopy.