Diffractive Imaging of Coherent Nuclear Motion in Isolated Molecules

TL;DR

This paper demonstrates ultrafast electron diffraction to image nuclear wavepacket motion in isolated iodine molecules, achieving high spatial and temporal resolution to observe vibrational dynamics during chemical reactions.

Contribution

It introduces a novel diffractive imaging technique capable of capturing both the position and shape of nuclear wavepackets in molecules with high precision.

Findings

Measured interatomic distances with 0.07 Å accuracy

Achieved 230 fs temporal resolution

Imaged nuclear wavepacket shape and motion

Abstract

Observing the motion of the nuclear wavepackets during a molecular reaction, in both space and time, is crucial for understanding and controlling the outcome of photoinduced chemical reactions. We have imaged the motion of a vibrational wavepacket in isolated iodine molecules using ultrafast electron diffraction with relativistic electrons. The time-varying interatomic distance was measured with a precision 0.07 {\AA} and temporal resolution of 230 fs full-width at half-maximum (FWHM). The method is not only sensitive to the position but also the shape of the nuclear wavepacket.