Dresden 2011 – scientific programme
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O: Fachverband Oberflächenphysik
O 85: Electron and spin dynamics I
O 85.3: Talk
Thursday, March 17, 2011, 17:00–17:15, WIL A317
(contribution withdrawn) Set in time of quasiparticle decay — •Yaroslav Pavlyukh1, Angel Rubio2, and Jamal Berakdar1 — 1Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle — 2Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Dpto. Física de Materiales, Universidad del País Vasco, CFM- CSIC-UPV/EHU-MPC and DIPC, Av. Tolosa 72, E-20018 San Sebastián, Spain
The initial stages of the quasiparticle decay in a Fermi liquid are governed by a time-scale distinct from the scattering rates as derived from the Fermi golden rule approach. We show that the initial decay is nonexponential and that it is determined by the zeroth spectral moment of the electron self-energy. In contrast to the imaginary part of the on-shell self-energy yielding the exponential decay, the spectral moment does not depend on the artificially introduced broadening, and, thus, can be used to characterize even very small finite system with fragmented states. We performed exact and approximate configuration interaction calculations of the spectral moments of the electron self-energy and devised a numerically simple approach for computing the spreading of quasiparticle states even for very large systems.