Attosecond metrology of 2D charge distribution in molecules

TL;DR

This study uses attosecond interferometry to measure charge distribution dynamics in 2D molecules, revealing unexpectedly smaller photoionization delays compared to 3D structures, enabling precise molecular dimension measurements.

Contribution

It demonstrates that 2D molecular systems exhibit unique photoionization delay behaviors, providing a new method to analyze ultrafast charge dynamics and spatial charge distribution with high precision.

Findings

2D naphthalene shows smaller photoionization delays than 3D diamond-like molecules.

Measured delays reveal the spatial distribution of the created hole with angstrom accuracy.

Findings enable tracking and manipulation of ultrafast charge transport in molecular materials.

Abstract

Photoionization as a half-scattering process is not instantaneous. Usually, time delays in photoionization are of the order of few tens of attoseconds (1 as = 10$^{-18}$ s). While going from a single atom to a nano-object, one can expect the delay to increase since the photoelectron scatters over a larger distance. Here, we show that this is no longer valid in the case of planar systems. Using attosecond interferometry, we find that the time delay in a 2D carbon-based molecule, naphthalene, is significantly smaller compared to its 3D diamond-like counterpart, adamantane. The measured time delay carries the signature of the spatial distribution of the hole created in the residual molecular cation, allowing us to obtain its dimensions with angstrom accuracy. Our findings offer novel opportunities for tracking and manipulating ultrafast charge transport in molecular materials.