@article{KuehnMuellerSorgenfreietal.2019, author = {K{\"u}hn, Danilo and M{\"u}ller, Moritz and Sorgenfrei, Florian and Giangrisostomi, Erika and Jay, Raphael Martin and Ovsyannikov, Ruslan and Martensson, Nils and Sanchez-Portal, Daniel and F{\"o}hlisch, Alexander}, title = {Directional sub-femtosecond charge transfer dynamics and the dimensionality of 1T-TaS2}, series = {Scientific reports}, volume = {9}, journal = {Scientific reports}, number = {488}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-018-36637-0}, pages = {9}, year = {2019}, abstract = {For the layered transition metal dichalcogenide 1T-TaS2, we establish through a unique experimental approach and density functional theory, how ultrafast charge transfer in 1T-TaS2 takes on isotropic three-dimensional character or anisotropic two-dimensional character, depending on the commensurability of the charge density wave phases of 1T-TaS2. The X-ray spectroscopic core-hole-clock method prepares selectively in-and out-of-plane polarized sulfur 3p orbital occupation with respect to the 1T-TaS2 planes and monitors sub-femtosecond wave packet delocalization. Despite being a prototypical two-dimensional material, isotropic three-dimensional charge transfer is found in the commensurate charge density wave phase (CCDW), indicating strong coupling between layers. In contrast, anisotropic two-dimensional charge transfer occurs for the nearly commensurate phase (NCDW). In direct comparison, theory shows that interlayer interaction in the CCDW phase - not layer stacking variations - causes isotropic three-dimensional charge transfer. This is presumably a general mechanism for phase transitions and tailored properties of dichalcogenides with charge density waves.}, language = {en} } @article{KuehnSorgenfreiGiangrisostomietal.2018, author = {K{\"u}hn, Danilo and Sorgenfrei, Florian and Giangrisostomi, Erika and Jay, Raphael and Musazay, Abdurrahman and Ovsyannikov, Ruslan and Strahlman, Christian and Svensson, Svante and M{\aa}rtensson, Nils and F{\"o}hlisch, Alexander}, title = {Capabilities of angle resolved time of flight electron spectroscopy with the 60 degrees wide angle acceptance lens}, series = {Journal of electron spectroscopy and related phenomena : the international journal on theoretical and experimental aspects of electron spectroscopy}, volume = {224}, 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.2017.06.008}, pages = {45 -- 50}, year = {2018}, abstract = {The simultaneous detection of energy, momentum and temporal information in electron spectroscopy is the key aspect to enhance the detection efficiency in order to broaden the range of scientific applications. Employing a novel 60 degrees wide angle acceptance lens system, based on an additional accelerating electron optical element, leads to a significant enhancement in transmission over the previously employed 30 degrees electron lenses. Due to the performance gain, optimized capabilities for time resolved electron spectroscopy and other high transmission applications with pulsed ionizing radiation have been obtained. The energy resolution and transmission have been determined experimentally utilizing BESSY II as a photon source. Four different and complementary lens modes have been characterized. (C) 2017 The Authors. Published by Elsevier B.V.}, language = {en} } @misc{RuscheBielawskiRiemannetal.2010, author = {Rusche, Tim Maxian and Bielawski, Martina and Riemann, Silke and Reimers, Lutz and Duplouy, Florent and Kuhn, Florian and von Oettingen, Anna}, title = {Deutsche Interessen offen diskutieren!}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41636}, year = {2010}, abstract = {Außenpolitik ist von den Werten, dem Selbstverst{\"a}ndnis einer Gesellschaft und den {\"o}konomischen Interessen ihrer Volkswirtschaft gepr{\"a}gt. In den ersten beiden Teilen dieses Essays zeigen wir auf, wie Deutschland seine Werte behutsam erneuern sollte und welche Bereiche zur Wahrung seines {\"o}konomischen Wohlstands zentral sind. Auf dieses Fundament setzen wir ein Pl{\"a}doyer f{\"u}r eine neue außenpolitische Kultur, die Interessen offen debattiert und klar definiert, um sie erfolgreich durchzusetzen.}, language = {de} } @article{KuehnGiangrisostomiJayetal.2019, author = {K{\"u}hn, Danilo and Giangrisostomi, Erika and Jay, Raphael Martin and Sorgenfrei, Florian and F{\"o}hlisch, Alexander}, title = {The influence of x-ray pulse length on space-charge effects in optical pump/x-ray probe photoemission}, series = {New journal of physics : the open-access journal for physics}, volume = {21}, journal = {New journal of physics : the open-access journal for physics}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {1367-2630}, doi = {10.1088/1367-2630/ab2f5c}, pages = {12}, year = {2019}, abstract = {Pump-probe photoelectron spectroscopy (PES) is a versatile tool to investigate the dynamics of transient states of excited matter. Vacuum space-charge effects can mask these dynamics and complicate the interpretation of electron spectra. Here we report on space-charge effects in Au 4f photoemission from a polycrystalline gold surface, excited with moderately intense 90 ps (FWHM) soft x-ray probe pulses, under the influence of the Coulomb forces exerted by a pump electron cloud, which was produced by intense 40 fs laser pulses. The experimentally observed kinetic energy shift and spectral broadening of the Au 4f lines, measured with highly-efficient time-of-flight spectroscopy, are in good agreement with simulations utilizing a mean-field model of the electrostatic pump electron potential. This confirms that the line broadening is predominantly caused by variations in the take-off time of the probe electrons without appreciable influence of local scattering events. Our findings might be of general interest for pump-probe PES with picosecond-pulse-length sources.}, language = {en} } @misc{KuehnSorgenfreiGiangrisostomietal.2018, author = {K{\"u}hn, Danilo and Sorgenfrei, Florian and Giangrisostomi, Erika and Jay, Raphael Martin and Musazayb, Abdurrahman and Ovsyannikov, Ruslan and Str{\aa}hlman, Christian and Svensson, Svante and M{\aa}rtensson, Nils and F{\"o}hlisch, Alexander}, title = {Capabilities of angle resolved time of flight electron spectroscopy with the 60 degrees wide angle acceptance lens}, series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {782}, issn = {1866-8372}, doi = {10.25932/publishup-43662}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-436629}, pages = {45 -- 50}, year = {2018}, abstract = {The simultaneous detection of energy, momentum and temporal information in electron spectroscopy is the key aspect to enhance the detection efficiency in order to broaden the range of scientific applications. Employing a novel 60 degrees wide angle acceptance lens system, based on an additional accelerating electron optical element, leads to a significant enhancement in transmission over the previously employed 30 degrees electron lenses. Due to the performance gain, optimized capabilities for time resolved electron spectroscopy and other high transmission applications with pulsed ionizing radiation have been obtained. The energy resolution and transmission have been determined experimentally utilizing BESSY II as a photon source. Four different and complementary lens modes have been characterized. (C) 2017 The Authors. Published by Elsevier B.V.}, language = {en} } @article{StedeKuhn2009, author = {Stede, Manfred and Kuhn, Florian}, title = {Identifying the content zones of German court decisions}, isbn = {978-3-642- 03423-7}, year = {2009}, language = {en} } @article{RuscheDuplouyKuhnetal.2011, author = {Rusche, Tim Maxian and Duplouy, Florent and Kuhn, Florian and von Oettingen, Anna}, title = {Deutsche Interessen}, series = {WeltTrends-Papiere}, journal = {WeltTrends-Papiere}, number = {20}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1864-0656}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-62837}, pages = {56 -- 59}, year = {2011}, abstract = {Inhalt: Interessen, Werte und Normen bedingen sich wechselseitig! Werte und Normen lassen sich als Interessen definieren! Debattenkultur gegen das Informationsdefizit! Was ist deutsch an deutschen Interessen?}, language = {de} } @book{SchroederSchellhardtAkincietal.2015, author = {Schroeder, Christoph and Schellhardt, Christin and Akinci, Mehmet-Ali and Dollnick, Meral and Dux, Ginesa and G{\"u}lbeyaz, Esin I{\c{s}}{\i}l and J{\"a}hnert, Anne and Ko{\c{c}}-G{\"u}lt{\"u}rk, Ceren and K{\"u}hmstedt, Patrick and Kuhn, Florian and Mezger, Verena and Pfaff, Carol and {\"U}rkmez, Bet{\"u}l Sena}, title = {MULTILIT}, editor = {Schroeder, Christoph and Schellhardt, Christin}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-80390}, publisher = {Universit{\"a}t Potsdam}, year = {2015}, abstract = {This paper presents an overview of the linguistic analyses developed in the MULTILIT project and the processing of the oral and written texts collected. The project investigates the language abilities of multilingual children and adolescents, in particular, those who have Turkish and/or Kurdish as a mother tongue. A further aim of the project is to examine from a psycholinguistic and sociolinguistic perspective the extent to which competence in academic registers is achieved on the basis of the languages spoken by the children, including the language(s) spoken at the home, the language of the country of residence and the first foreign language. To be able to examine these questions using corpus linguistic parameters, we created categories of analysis in MULTILIT. The data collection comprises texts from bilingual and monolingual children and adolescents in Germany in their first language Turkish, their second language German und their foreign language English. Pupils aged between nine and twenty years of age produced monologue oral and written texts in the two genres of narrative and discursive. On the basis of these samples, we examine linguistic features such as lexical expression (lexical density, lexical diversity), syntactic complexity (syntactic and discursive packaging) as well as phonology in the oral texts and orthography in the written texts, with the aim of investigating the pupils' growing mastery of these features in academic and informal registers. To this end the raw data have been transcribed by the use of transcription conventions developed especially for the needs of the MULTILIT data. They are based on the commonly used HIAT and GAT transcription conventions and supplemented with conventions that provide additional information such as features at the graphic level. The categories of analysis comprise a large number of linguistic categories such as word classes, syntax, noun phrase complexity, complex verbal morphology, direct speech and text structures. We also annotate errors and norm deviations at a wide range of levels (orthographic, morphological, lexical, syntactic and textual). In view of the different language systems, these criteria are considered separately for all languages investigated in the project.}, language = {en} } @article{Kuehn2007, author = {K{\"u}hn, Florian P.}, title = {Mehr Politik!}, series = {WeltTrends-Papiere}, journal = {WeltTrends-Papiere}, number = {5}, issn = {1864-0656}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-31761}, pages = {41 -- 46}, year = {2007}, abstract = {Inhalt: - Welche Staatlichkeit? - Gewalt folgt einer eigenen Logik - Beispiel Afghanistan - Mehr Sicherheit? F{\"u}r wen? - Risiko ist keine Bedrohung - Nassauer hat Recht und zugleich Unrecht}, language = {de} } @article{BeyeOebergXinetal.2016, author = {Beye, Martin and {\"O}berg, Henrik and Xin, Hongliang and Dakovski, Georgi L. and F{\"o}hlisch, Alexander and Gladh, Jorgen and Hantschmann, Markus and Hieke, Florian and Kaya, Sarp and K{\"u}hn, Danilo and LaRue, Jerry and Mercurio, Giuseppe and Minitti, Michael P. and Mitra, Ankush and Moeller, Stefan P. and Ng, May Ling and Nilsson, Anders and Nordlund, Dennis and Norskov, Jens and {\"O}str{\"o}m, Henrik and Ogasawara, Hirohito and Persson, Mats and Schlotter, William F. and Sellberg, Jonas A. and Wolf, Martin and Abild-Pedersen, Frank and Pettersson, Lars G. M. and Wurth, Wilfried}, title = {Chemical Bond Activation Observed with an X-ray Laser}, series = {The journal of physical chemistry letters}, volume = {7}, journal = {The journal of physical chemistry letters}, publisher = {American Chemical Society}, address = {Washington}, issn = {1948-7185}, doi = {10.1021/acs.jpclett.6b01543}, pages = {3647 -- 3651}, year = {2016}, abstract = {The concept of bonding and antibonding orbitals is fundamental in chemistry. The population of those orbitals and the energetic difference between the two reflect the strength of the bonding interaction. Weakening the bond is expected to reduce this energetic splitting, but the transient character of bond-activation has so far prohibited direct experimental access. Here we apply time-resolved soft X-ray spectroscopy at a free electron laser to directly observe the decreased bonding antibonding splitting following bond-activation using an ultrashort optical laser pulse.}, language = {en} }