Attosecond dispersive soft X-ray absorption fine structure spectroscopy in graphite

TL;DR

This paper introduces attoXAFS, a novel attosecond soft X-ray spectroscopy technique that enables real-time correlation of electronic states and atomic structure in materials like graphite, advancing understanding of photo-induced processes.

Contribution

The work demonstrates the first application of water-window-range attosecond X-ray pulses for dispersive XAFS, revealing electronic and lattice dynamics simultaneously in graphite.

Findings

Identification of σ* and π* orbital contributions in graphite

Simultaneous measurement of electronic states and lattice distances

Validation of attoXAFS as a versatile real-time investigative tool

Abstract

Phase transitions of solids and structural transformations of molecules are canonical examples of important photo-induced processes, whose underlying mechanisms largely elude our comprehension due to our inability to correlate electronic excitation with atomic position in real time. Here, we present a decisive step towards such new methodology based on water-window-covering (284 eV to 543 eV) attosecond soft X-ray pulses that can simultaneously access electronic and lattice parameters via dispersive X-ray absorption fine-structure (XAFS) spectroscopy. We validate attoXAFS with an identification of the {\sigma}* and {\pi}* orbital contributions to the density of states in graphite simultaneously with its lattice's four characteristic bonding distances. This work demonstrates the concept of attoXAFS as a powerful real-time investigative tool which is equally applicable to gas-, liquid- and condensed phase.