Regensburg 2004 – wissenschaftliches Programm
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O: Oberflächenphysik
O 11: Elektronische Struktur (Experiment und Theorie) I
O 11.2: Vortrag
Montag, 8. März 2004, 16:00–16:15, H44
Electron phonon coupling and electron correlations in the adsorbate system Cu(100)c(2x2)N — •Thordis Michalke, Jürgen Hager, and René Matzdorf — Institut für Physik, Universität Kassel
We investigated the self organized nanopatterned surface of nitrogen covered Cu(100) by means of photoelectron spectroscopy (PES), scanning tunneling microscopy (STM) and spectroscopy (STS).
With STS we imaged the local density of states of certain eigenstates in the 5x5 nm2 islands. The quasi particle lifetime of these states was measured in dependence of their quantum number, and the effective mass has been determined to be m⋆=1.1 m0.
In photoelectron spectra one can observe several adsorbate induced states. Temperature dependent measurements show that these two dimensional states couple strongly to phonons. The mass enhancement factor was calculated with the Einstein model and known phonon energy of 40 meV to be between λ = 0.5 and λ = 1.4 for different states. One of the adsorbate states shows exceptional behaviour when approaching the Fermi energy. Here the band renormalization due to electron phonon coupling may be visible.