Correlation-driven sub-3 fs charge migration in ionised adenine

TL;DR

This study provides the first experimental evidence of correlation-driven charge migration in adenine, observed via time-resolved measurements and supported by simulations, revealing ultrafast electron dynamics relevant for controlling molecular reactivity.

Contribution

It demonstrates the real-time observation of charge migration in adenine after ionisation, combining experimental data with first-principles simulations to reveal electron correlation effects.

Findings

Charge migration occurs within a few femtoseconds after ionisation.

Doubly charged adenine indicates a charge inflation mechanism.

First-principles simulations support experimental observations.

Abstract

Sudden ionisation of a relatively large molecule can initiate a correlation-driven process dubbed charge migration, where the electron density distribution is expected to rapidly change. Capturing this few-femtosecond/attosecond charge redistribution represents the real-time observation of the electron correlation in the molecule. So far, there has been no experimental evidence of this process. Here we report on a time-resolved study of the correlation-driven charge migration process occurring in the bio-relevant molecule adenine after ionisation by a 15-35 eV attosecond pulse . We find that, the production of intact doubly charged adenine - via a shortly-delayed laser-induced second ionisation event - represents the signature of a charge inflation mechanism resulting from the many-body excitation. This conclusion is supported by first-principles time-dependent simulations. Our findings opens new important perspectives for the control of the molecular reactivity at the electronic timescale.