@article{KoenneckeFollathPontiusetal.2013,
  author    = {K{\"o}nnecke, Rene and Follath, R. and Pontius, N. and Schlappa, J. and Eggenstein, F. and Zeschke, T. and Bischoff, P. and Schmidt, J. -S. and Noll, T. and Trabant, C. and Schreck, S. and Wernet, Ph. and Eisebitt, S. and Senf, F. and Schuessler-Langeheine, Christian and Erko, A. and F{\"o}hlisch, Alexander},
  title     = {The confocal plane grating spectrometer at BESSY II},
  series = {Journal of electron spectroscopy and related phenomena : the international journal on theoretical and experimental aspects of electron spectroscopy},
  volume    = {188},
  journal   = {Journal of electron spectroscopy and related phenomena : the international journal on theoretical and experimental aspects of electron spectroscopy},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0368-2048},
  doi       = {10.1016/j.elspec.2012.11.003},
  pages     = {133 -- 139},
  year      = {2013},
  abstract  = {At BESSY II a confocal plane grating spectrometer for resonant inelastic X-ray scattering (RIXS) is currently under commissioning. The new endstation operates with a source size of 4 x 1 mu m(2) provided by its dedicated beamline. The RIXS-spectrometer covers an energy range from 50 eV to 1000 eV, providing a resolving power E/Delta E of 5000-15,000. The beamline allows full polarization control and gives a photon flux of up to 7 x 10(14) photons/s/0.1 A/0.1\%bandwidth by offering a resolving power E/Delta E of 4000-12,000.},
  language  = {en}
}
@article{KunnusJosefssonSchrecketal.2017,
  author    = {Kunnus, Kristjan and Josefsson, I. and Schreck, Simon Frederik and Quevedo, W. and Miedema, P. S. and Techert, S. and de Groot, F. M. F. and F{\"o}hlisch, Alexander and Odelius, M. and Wernet, Ph.},
  title     = {Quantifying covalent interactions with resonant inelastic soft X-ray scattering},
  series = {Chemical physics letters},
  volume    = {669},
  journal   = {Chemical physics letters},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0009-2614},
  doi       = {10.1016/j.cplett.2016.12.046},
  pages     = {196 -- 201},
  year      = {2017},
  abstract  = {We analyze the effects of covalent interactions in Ni 2p3d resonant inelastic X-ray scattering (RIXS) spectra from aqueous Ni2+ ions and find that the relative RIXS intensities of ligand-to-metal charge-transfer final states with respect to the ligand-field final states reflect the covalent mixing between Ni 3d and water orbitals. Specifically, the experimental intensity ratio at the Ni L-3-edge allows to determine that the Ni 3d orbitals have on average 5.5\% of water character. We propose that 2p3d RIXS at the Ni L-3-edge can be utilized to quantify covalency in Ni complexes without the use of external references or simulations.},
  language  = {en}
}
@article{BeyeWernetSchuesslerLangeheineetal.2013,
  author    = {Beye, Martin and Wernet, Ph. and Sch{\"u}ßler-Langeheine, Christian and F{\"o}hlisch, Alexander},
  title     = {Time resolved resonant inelastic X-ray scattering: a supreme tool to understand dynamics in solids and molecules},
  series = {Journal of electron spectroscopy and related phenomena : the international journal on theoretical and experimental aspects of electron spectroscopy},
  volume    = {188},
  journal   = {Journal of electron spectroscopy and related phenomena : the international journal on theoretical and experimental aspects of electron spectroscopy},
  number    = {3},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0368-2048},
  doi       = {10.1016/j.elspec.2013.04.013},
  pages     = {172 -- 182},
  year      = {2013},
  abstract  = {Dynamics in materials typically involve different degrees of freedom, like charge, lattice, orbital and spin in a complex interplay. Time-resolved resonant inelastic X-ray scattering (RIXS) as a highly selective tool can provide unique insight and follow the details of dynamical processes while resolving symmetries, chemical and charge states, momenta, spin configurations, etc. In this paper, we review examples where the intrinsic scattering duration time is used to study femtosecond phenomena. Free-electron lasers access timescales starting in the sub-ps range through pump-probe methods and synchrotrons study the time scales longer than tens of ps. In these examples, time-resolved resonant inelastic X-ray scattering is applied to solids as well as molecular systems.},
  language  = {en}
}
@article{BeyeFoehlisch2013,
  author    = {Beye, Martin and F{\"o}hlisch, Alexander},
  title     = {Soft X-ray probes of ultrafast dynamics for heterogeneous catalysis},
  series = {Chemical physics : a journal devoted to experimental and theoretical research involving problems of both a chemical and physical nature},
  volume    = {414},
  journal   = {Chemical physics : a journal devoted to experimental and theoretical research involving problems of both a chemical and physical nature},
  number    = {5},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0301-0104},
  doi       = {10.1016/j.chemphys.2012.03.023},
  pages     = {130 -- 138},
  year      = {2013},
  abstract  = {Soft X-ray spectroscopy is one of the best tools to directly address the electronic structure, the driving force of chemical reactions. It enables selective studies on sample surfaces to single out reaction centers in heterogeneous catalytic reactions. With core-hole clock methods, specific dynamics are related to the femtosecond life time of a core-hole. Typically, this method is used with photoemission spectroscopy, but advancements in soft X-ray emission techniques render more specific studies possible. With the advent of bright femtosecond pulsed soft X-ray sources, highly selective pump-probe X-ray emission studies are enabled with temporal resolutions down to tens of femtoseconds. This finally allows to study dynamics in the electronic structure of adsorbed reaction centers on the whole range of relevant time scales - closing the gap between kinetic soft X-ray studies and the atto- to femtosecond core-hole clock techniques.},
  language  = {en}
}
@article{BeyeFoehlisch2011,
  author    = {Beye, Martin and F{\"o}hlisch, Alexander},
  title     = {A soft X-ray approach to electron-phonon interactions beyond the Born-Oppenheimer approximation},
  series = {Journal of electron spectroscopy and related phenomena : the international journal on theoretical and experimental aspects of electron spectroscopy},
  volume    = {184},
  journal   = {Journal of electron spectroscopy and related phenomena : the international journal on theoretical and experimental aspects of electron spectroscopy},
  number    = {3-6},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0368-2048},
  doi       = {10.1016/j.elspec.2010.12.032},
  pages     = {313 -- 317},
  year      = {2011},
  abstract  = {With modern soft X-ray methods, the whole field of electron-phonon interactions becomes accessible directly in the ultrafast time domain with ultrashort pulsed X-ray sources, as well as in the energy domain through modern highly resolving spectrometers. The well-known core-hole clock approach plays an intermediate role, resolving energetic and temporal features at the same time. In this perspective paper, we review several experiments to illustrate the modern advances in the selective study of electron-phonon interactions as fundamentally determining ingredients for materials properties. We present the different complementary approaches that can be taken with soft X-ray methods to conquer this field beyond the Born-Oppenheimer approximation.},
  language  = {en}
}