Regensburg 2010 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
O: Fachverband Oberflächenphysik
O 45: Electronic structure I
O 45.7: Talk
Wednesday, March 24, 2010, 12:00–12:15, H33
Neutral Excitations of Physisorbed Helium — •Sarah Kossler1, Reinhold Schneider1, Peter Feulner1, and Jean Pierre Gauyacq2 — 1TU München, Garching, Germany — 2UMR CNRS-Université Paris Sud, Orsay, France
We study neutral excitations of He mono- and bilayers on Pt(111), Ru(001), Ag(111) and Cu(111) surfaces, and sandwich layers of He on well ordered Ne and Ar monolayers on these substrates. We apply narrow bandwidth undulator radiation of variable polarization (BESSY, UE-112-PGM-1) in combination with a Time-Of-Flight technique that enables us to detect electrons, ions, metastable atoms and fluorescence photons. Therewith we obtain comprehensive data sets on excitation and decay processes below the 1s ionization edges of these layers. Compared to the isolated atom, strong inter- and intralayer coupling is found that is well reproduced by calculations. We observe hybridization of s and p final states, and for higher principal quantum numbers also admixture of d states. We demonstrate that the comparison of data from different samples as indicated above is indispensable for a complete understanding of these processes.
Support by the Deutsche Forschungsgemeinschaft (Fe346/2-1), travel funding by the HZB, and help during the experiment by N.Armbrust, D.Heim and the staff of BESSY is gratefully acknowledged.