Regensburg 2010 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 8: CE: (General) Theory

TT 8.10: Vortrag

Montag, 22. März 2010, 16:30–16:45, H21

LSDA+DMFT calculations of electron phonon coupling and its combination with one step model of photoemission — •Jan Minar¹, J. Braun¹, S. Mankovskyy¹, H. Ebert¹, R. Ovsyannikov², H. A. Duerr², and J. Fink² — ¹Dep. Chemie und Biochemie, LMU University of Munich, Germany — ²Helmholtz-Zentrum Berlin, Albert-Einstein-Strasse 15, 12489 Berlin, Germany

Recent developments and improvements in the resolution of angle-resolved UPS and XPS photoemission experiments require an improved (or revised) theoretical description of the photoemission process in the framework of the one-step model. In particular, the combination of the KKR band structure method with the dynamical mean field theory (DMFT) provides a quantitative interpretation of photoemission data including all matrix elements effects. Here, we present a formalism that allows to include lattice vibrations into the one-step model. In the UPS regime electron-phonon interaction is reflected by kinks and related phenomena. Calculation of the force-constant tensor within the KKR Green's function method gives access to the k-resolved Eliashberg function and an electron-phonon self-energy. This quantity can be included into the photoemission formalism. The method has been applied to angle-resolved photoemission from Ni(111) and is compared to corresponding experimental data. In contrary to the standard interpretations we found a considerable impact on the electron-phonon self-energy due to spin-flip processes that are induced by spin-orbit coupling. We also show that inclusion of correlations effects is crucial in order to describe electron phonon coupling in Ni.