Schweda, Simon

[["dc.bibliographiccitation.firstpage","200"],["dc.bibliographiccitation.issue","6193"],["dc.bibliographiccitation.journal","Science"],["dc.bibliographiccitation.lastpage","204"],["dc.bibliographiccitation.volume","345"],["dc.contributor.author","Gulde, Max"],["dc.contributor.author","Schweda, Simon"],["dc.contributor.author","Storeck, Gero"],["dc.contributor.author","Maiti, Manisankar"],["dc.contributor.author","Yu, H. K."],["dc.contributor.author","Wodtke, Alec Michael"],["dc.contributor.author","Schaefer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2018-11-07T09:37:44Z"],["dc.date.available","2018-11-07T09:37:44Z"],["dc.date.issued","2014"],["dc.description.abstract","Two-dimensional systems such as surfaces and molecular monolayers exhibit a multitude of intriguing phases and complex transitions. Ultrafast structural probing of such systems offers direct time-domain information on internal interactions and couplings to a substrate or bulk support. We have developed ultrafast low-energy electron diffraction and investigate in transmission the structural relaxation in a polymer/graphene bilayer system excited out of equilibrium. The laser-pump/electron-probe scheme resolves the ultrafast melting of a polymer superstructure consisting of folded-chain crystals registered to a free-standing graphene substrate. We extract the time scales of energy transfer across the bilayer interface, the loss of superstructure order, and the appearance of an amorphous phase with short-range correlations. The high surface sensitivity makes this experimental approach suitable for numerous problems in ultrafast surface science."],["dc.identifier.doi","10.1126/science.1250658"],["dc.identifier.isi","000339409900050"],["dc.identifier.pmid","25013072"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32904"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation","SFB 1073: Kontrolle von Energiewandlung auf atomaren Skalen"],["dc.relation","SFB 1073 | Topical Area A | A05 Nanoskalige Untersuchung raumzeitlicher Relaxation in heterogenen Systemen mit ultraschneller Transmissionselektronenmikroskopie"],["dc.relation.issn","1095-9203"],["dc.relation.issn","0036-8075"],["dc.title","Ultrafast low-energy electron diffraction in transmission resolves polymer/graphene superstructure dynamics"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Journal of Applied Physics"],["dc.bibliographiccitation.volume","112"],["dc.contributor.author","Paarmann, A."],["dc.contributor.author","Gulde, M."],["dc.contributor.author","Mueller, M."],["dc.contributor.author","Schäfer, S."],["dc.contributor.author","Schweda, S."],["dc.contributor.author","Maiti, M."],["dc.contributor.author","Xu, C."],["dc.contributor.author","Hohage, T."],["dc.contributor.author","Schenk, F."],["dc.contributor.author","Ropers, C."],["dc.contributor.author","Ernstorfer, R."],["dc.date.accessioned","2017-09-07T11:52:59Z"],["dc.date.available","2017-09-07T11:52:59Z"],["dc.date.issued","2012"],["dc.description.abstract","We numerically investigate the properties of coherent femtosecond single electron wave packets photoemitted from nanotips in view of their application in ultrafast electron diffraction and non-destructive imaging with low-energy electrons. For two different geometries, we analyze the temporal and spatial broadening during propagation from the needle emitter to an anode, identifying the experimental parameters and challenges for realizing femtosecond time resolution. The simple tip-anode geometry is most versatile and allows for electron pulses of several ten of femtosecond duration using a very compact experimental design, however, providing very limited control over the electron beam collimation. A more sophisticated geometry comprising a suppressor-extractor electrostatic unit and a lens, similar to typical field emission electron microscope optics, is also investigated, allowing full control over the beam parameters. Using such a design, we find ∼230 fs pulses feasible in a focused electron beam. The main limitation to achieve sub-hundred femtosecond time resolution is the typical size of such a device, and we suggest the implementation of more compact electron optics for optimal performance."],["dc.identifier.doi","10.1063/1.4768204"],["dc.identifier.gro","3146392"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4161"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","chake"],["dc.relation.orgunit","Institut für Numerische und Angewandte Mathematik"],["dc.title","Coherent femtosecond low-energy single-electron pulses for time-resolved diffraction and imaging: A numerical study"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]