Regensburg 2004 – wissenschaftliches Programm
O 37.3: Vortrag
Donnerstag, 11. März 2004, 16:15–16:30, H36
Lifetimes of quasiparticle excitations in 4d transition metals Mo and Rh — •Alexander Mönnich, Daniela Bayer, Michael Bauer, and Martin Aeschlimann — Dep. of Physics, University of Kaiserslautern, D-67663 Kaiserslautern
The dynamics of excited electrons in metals are crucial for a detailed understanding of various chemical and physical phenomena on metal surfaces. It is already known that noble metals show a longer lifetime of quasiparticle excitations than transition metals due to the higher density-of-states around the Fermi level. But also the electron dynamics between different transition metals can exhibit significant divergences.
With the time resolved two-photon photoelectron spectroscopy (TR-2PPE) method we investigated the electron dynamics of Mo and Rh in an energy range up to 3 eV above the Fermi level. LMTO-RPG-GW calculations predict a surprising large difference between the averaged lifetimes of electron quasiparticles in the 4d transition metals Mo and Rh  that were confirmed in our experiment. The characteristics of electronic structure responsible for energy dissipation processes of hot electrons will be discussed.
 V. P. Zhukov, F. Aryasetiawan, E. V. Chulkov, P. M. Enchenique PRB 65 11511 (2002)