DARWIN Digitale Dissertationen German Version Strich

FU Berlin
Digitale Dissertation

Robert Keyling :
Ab-initio calculation of the ultrafast dynamics of excited electrons in bulk and surface states of metals
Ab-initio Berechnung der ultraschnellen Dynamik angeregter Elektronen in Volumen- und Oberflächenzuständen von Metallen

 FU Logo

|Abstract| |Table of Contents| |More Information|

Abstract

This work addresses the calculation of electronic properties of many-body systems at the example of various metals. In addition to the ground-state properties the work focuses on the dynamics of excited states, especially the lifetime of excited electrons. Common starting point for all calculations is a careful determination of the electronic ground state, which is followed by the calculation of the excited states using many-body perturbation theory. The computation of the ground state is done within density-functionaltheory (DFT) utilizing the local- density approximation (LDA). Typically a pseudopotential formalism is used and it has been checked that this leads to results, which compare very well to those of all-electron methods. In this work the lifetime of excited states in simple metals and noble metals are discussed. Furthermore, the lifetime of electrons in surface states of noble metals are considered. In order to calculate the properties of surfaces the supercell method has been used. Slabs have been constructed and the ground states of the three low-indexed surfaces of the fcc metals Al and the noble metals have been calculated. In this context many tests concerning the slab and vacuum thicknesses, respectively, have been performed. The excited states are described using the Dyson equation, where the self-energy is calculated within the GW approximation. The results of these GW calculations for both, bulk and surface systems, agree well with experimental results.

Table of Contents

Download the whole PhDthesis as a zip-tar file or as zip-File

For download in PDF format click the chapter title

0. Titelblatt, Inhaltsverzeichnis
1. Einleitung 7
2. Vielteilchentheorie 11
      2.1.    Der Hamiltonoperator, die Wellenfunktion 11
      2.2.    Der Grundzustand 13
         2.2.1       Die Dichtefunktionaltheorie 13
         2.2.2.       Die selbstkonsistenten Gleichungen 14
         2.2.3.       Die lokale Dichteapproximation 16
      2.3.    Methoden der Grundzustandsberechnung 17
         2.3.1.       Die LAPW-Methode 17
         2.3.2.       Die PW-Methode 17
      2.4.    Der angeregte Zustand 19
         2.4.1.       Die Dyson-Gleichung 19
         2.4.2.       Die Selbstenergie, die GW-Näherung 23
      2.5.    Die Fermi-Liquid-Theorie 24
3. Der unendlich ausgedehnte Festkörper 27
      3.1.    Die Brillouinsche-Zone des fcc-Gitters 27
      3.2.    Die Bandstruktur des Festkörpers 28
         3.2.1.       Aluminium 28
         3.2.2.       Silber 30
         3.2.3.       Gold 32
      3.3.    Die elektronische Dichte 34
      3.4.    Die Lebensdauer angeregter Zustände 36
4. Einleitung zu den Oberflächen 41
      4.1.    Die Superzelle, der Slab 41
      4.2.    Das Dehnen 43
      4.3.    Die Selbstenergie und Lebensdauern von Oberflächen 48
5. Die Oberflächen 51
      5.1.    Die (100)-Oberfläche 51
         5.1.1.       Die Bandstruktur 53
         5.1.2.       Das Austausch-Korrelationspotential 58
         5.1.3.       Die elektronische Dichte 61
         5.1.4.       Die Lebensdauer 67
   5.2.    Die (110)-Oberfläche 68
         5.2.1.       Die Bandstruktur 69
         5.2.2.       Das Austausch-Korrelationspotential 72
         5.2.3.       Die elektronische Dichte 74
         5.2.4.       Die Lebensdauer 75
      5.3.    Die (111)-Oberfläche 76
         5.2.1.       Die Bandstruktur 78
         5.3.2.       Das Austausch-Korrelationspotential 83
         5.3.3.       Die elektronische Dichte 85
         5.3.4.       Die Lebensdauer 86
6. Zusammenfassung und Ausblick 89
7. Appendix 91
8. Literatur 101

More Information:

Online available: http://www.diss.fu-berlin.de/2002/166/indexe.html
Language of PhDThesis: german
Keywords: femtosecond dynamics, lifetime of excited electrons, many-body theory, surface states, noble metals
DNB-Sachgruppe: 29 Physik, Astronomie
Classification PACS: 78.47.+p, 72.15.Lh, 71.10.-w, 71.20.Gj
Date of disputation: 15-Jul-2002
PhDThesis from: Fachbereich Physik, Freie Universität Berlin
First Referee: Prof. Dr. E.K.U. Gross
Second Referee: Prof. Dr. K.-H. Bennemann
Contact (Author): keyling@fhi-berlin.mpg.de
Contact (Advisor): hardy@physik.fu-berlin.de
Date created:27-Aug-2002
Date available:28-Aug-2002

 

|| DARWIN|| Digitale Dissertationen || Dissertation|| German Version|| FU Berlin|| Seitenanfang ||

Mail-Icon Fragen und Kommentare an:
darwin@inf.fu-berlin.de

© Freie Universität Berlin 1999