%0 Journal Article
%A Mazza, Tommaso
%A Ilchen, Markus
%A Kiselev, M. D.
%A Gryzlova, E. V.
%A Baumann, Thomas
%A Boll, Rebecca
%A De Fanis, A.
%A Grychtol, P.
%A Montaño, J.
%A Music, Valerija
%A Ovcharenko, Y.
%A Rennhack, N.
%A Rivas, D. E.
%A Schmidt, Philipp
%A Wagner, Rene
%A Ziolkowski, Pawel
%A Berrah, N.
%A Erk, Benjamin
%A Johnsson, P.
%A Küstner-Wetekam, C.
%A Marder, L.
%A Martins, Michael
%A Ott, Christian
%A Pathak, Shashank
%A Pfeifer, Thomas
%A Rolles, Daniel
%A Zatsarinny, O.
%A Grum-Grzhimailo, A. N.
%A Meyer, Michael
%T Mapping Resonance Structures in Transient Core-Ionized Atoms
%J Physical review / X
%V 10
%N 4
%@ 2160-3308
%C College Park, Md.
%I APS
%M PUBDB-2021-00009
%P 041056
%D 2020
%X 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. 
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000600284700002
%R 10.1103/PhysRevX.10.041056
%U https://bib-pubdb1.desy.de/record/453555