Objectif This grant application proposes the establishment of Ultrafast Low-Energy Electron Diffraction (ULEED) as a novel and versatile approach to investigate ultrafast structural dynamics at surfaces and in ultrathin films. Two-dimensional systems such as surfaces and molecular monolayers exhibit a multitude of intriguing phases and complex transitions. Studying the ultrafast dynamics of these materials elucidates correlations and microscopic couplings, but the access to structural degrees of freedom with ultrahigh time resolution remains challenging. Low-Energy Electron Diffraction (LEED) is a powerful technique in surface science to determine the atomic-scale structure and symmetry of surfaces. However, time-resolved LEED has proven exceedingly difficult to realize, owing to the problems in realizing suitable low-energy electron pulses of sufficiently short pulse duration and high beam quality.This project targets both of these present limitations by using laser-triggered nanoscopic electron sources to generate high-brightness beams of low-energy electrons. Specifically, nanotip cathodes driven by nonlinear photoemission will be integrated in compact micro- and nanofabricated electrostatic lens assemblies. This will allow for a drastic reduction of electron beam propagation distances while maintaining a high level of beam control and focusing ability. Using this electron source, we plan to develop a laser-pump/electron-diffraction-probe setup at low electron energies with a temporal resolution of few hundred femtoseconds and less. A number of strategies will be followed to improve the temporal resolution of the setup, including wavelength-tuning of the laser excitation and active spectral compression of the electron pulses using locally enhanced THz fields. We will apply ULEED in the investigation of the structural dynamics within a range surface systems, including molecular monolayers, intrinsic surface reconstructions and adsorbate-induced charge-density waves. Champ scientifique engineering and technologymaterials engineeringcoating and filmsnatural sciencesphysical sciencesopticslaser physics Programme(s) H2020-EU.1.1. - EXCELLENT SCIENCE - European Research Council (ERC) Main Programme Thème(s) ERC-StG-2014 - ERC Starting Grant Appel à propositions ERC-2014-STG Voir d’autres projets de cet appel Régime de financement ERC-STG - Starting Grant Institution d’accueil GEORG-AUGUST-UNIVERSITAT GOTTINGEN STIFTUNG OFFENTLICHEN RECHTS Contribution nette de l'UE € 1 479 750,00 Adresse WILHELMSPLATZ 1 37073 Gottingen Allemagne Voir sur la carte Région Niedersachsen Braunschweig Göttingen Type d’activité Higher or Secondary Education Establishments Liens Contacter l’organisation Opens in new window Site web Opens in new window Participation aux programmes de R&I de l'UE Opens in new window Réseau de collaboration HORIZON Opens in new window Coût total € 1 479 750,00 Bénéficiaires (1) Trier par ordre alphabétique Trier par contribution nette de l'UE Tout développer Tout réduire GEORG-AUGUST-UNIVERSITAT GOTTINGEN STIFTUNG OFFENTLICHEN RECHTS Allemagne Contribution nette de l'UE € 1 479 750,00 Adresse WILHELMSPLATZ 1 37073 Gottingen Voir sur la carte Région Niedersachsen Braunschweig Göttingen Type d’activité Higher or Secondary Education Establishments Liens Contacter l’organisation Opens in new window Site web Opens in new window Participation aux programmes de R&I de l'UE Opens in new window Réseau de collaboration HORIZON Opens in new window Coût total € 1 479 750,00
