Mapping Resonance Structures in Transient Core-Ionized Atoms

Tommaso Mazza ,Ph Schmidt,A De Fanis,N Berrah,J Montaño,M Martins,R Wagner,A N Grum–Grzhimailo ,T Baumann ,Benjamin Erk ,Catmarna Küstner-Wetekam ,Thomas Pfeifer ,Shashank Pathak ,Pawel Ziółkowski ,Daniel E Rivas ,Christian Ott ,Maksim D Kiselev ,Rebecca Boll ,Per Johnsson ,Lutz Marder ,Nils Rennhack ,Oleg Zatsarinny ,Elena V Gryzlova ,Markus Ilchen ,Y Ovcharenko ,Daniel Rolles ,Patrik Grychtol ,Valerija Music ,Michael Meyer

doi:10.1103/physrevx.10.041056

Abstract

The nature of transient electronic states created by photoabsorption critically determines the dynamics of the subsequently evolving system. Here, we investigate K-shell photoionized atomic neon by absorbing a second photon within the Auger-decay lifetime of 2.4 fs using the European XFEL, a unique high-repetition-rate, wavelength-tunable x-ray free-electron laser. By high-resolution electron spectroscopy, we map out the transient Rydberg resonances unraveling the details of the subsequent decay of the hollow atom. So far, ultra-short-lived electronic transients, which are often inaccessible by experiments, were mainly inferred from theory but are now addressed by nonlinear x-ray absorption. The successful characterization of these resonances with femtosecond lifetimes provides the basis for a novel class of site-specific, nonlinear, and time-resolved studies with strong impact for a wide range of topics in physics and chemistry. (Less)

Highlights

Transient electronic states play a crucial role in complex physical or chemical processes in atoms [1,2] and molecules [3,4,5,6,7], as well as photocatalysis [8,9], elementary steps in photosynthesis [10], and radiation damage [11]
The first step of lightmatter interaction is, predominantly, the photoemission of a core electron that alters the Coulombic potential of the targeted system within attoseconds. Such a core-ionized system typically decays within a few femtoseconds, which subsequently triggers a variety of processes
If another photon with sufficient energy is absorbed before the ultrafast relaxation, the remaining electron from the core orbital can be ejected or resonantly excited into a valence orbital, creating a double-core hole (DCH) [18]

Summary

Introduction

Transient electronic states play a crucial role in complex physical or chemical processes in atoms [1,2] and molecules [3,4,5,6,7], as well as photocatalysis [8,9], elementary steps in photosynthesis [10], and radiation damage [11]. In addition to providing the required time resolution for recording snapshot sequences of ultrafast processes at the atomic scale, they are suitable tools for creating, exploiting, and investigating transient structures and resonances, while giving access to site-specific information by element-specific core excitations in the soft x-ray regime [12]. At these short wavelengths, the first step of lightmatter interaction is, predominantly, the photoemission of a core electron that alters the Coulombic potential of the targeted system within attoseconds. Probing the electronic structure of a core-excited system before any relaxation occurs provides essential information

Methods

Results

Conclusion