Application of Many-Body Perturbation Theory to the Description of Correlated Metals

Chadov, Stanislav (2007): Application of Many-Body Perturbation Theory to the Description of Correlated Metals. Dissertation, LMU München: Fakultät für Chemie und Pharmazie

Abstract

An efficient computational LSDA+DMFT toolbox for the description of correlated materials has been established. The method developed in this work provides an appropriate description of 3d-transition metal correlated bulk systems, concerning their ground-state properties (magnetic moments, total energies) as well as the high- and low-energy spectroscopies (valence-band angular-resolved photoemission, Fano-effect, optical and magneto-optical properties). The incorporation of the perturbational impurity solvers within the spin-polarized relativistic Korringa-Kohn-Rostoker (SPR-KKR) Green’s function method gives rise to a fully self-consistent procedure with respect both to the DFT (charge) and the DMFT (localized dynamical self-energy) self-consistency requirements. Thus, the solution of the many-electron problem can be achieved with a high precision. In turn this opens a possibility to investigate very delicate properties, as the orbital magnetic moments of 3d-transition metals. To develop a relatively fast and accurate approach for the low-energy spectroscopies, the DMFT was implemented within the wave function formalism in the framework of the Linearized Muffin-Tin Orbitals method (LMTO). Calculations are performed in a one-shot run, that does not allow to get the charge-self-consistent solution. In such a way all effects of the localized correlations are encapsulated in the Green’s function constructed as a resolvent to the LMTO one-particle Hamiltonian and accounting for the corresponding self-energy via the Dyson equation. The LMTO+DMFT scheme gives in comparison to a plain LSDA a significantly improved description of the magneto-optics in the 3d-transition metals, half-metallic Heusler ferromagnet NiMnSb, as well as for the heavy-fermion US compound.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Keywords: local correlations, dynamical correlations, DFT, SDFT, DMFT, LSDA, LDA+U, LSDA+U, LSDA+DMFT, self-energy, Green's function, optical conductivity, magneto-optics, x-ray photoemission, Fano-effect, Galitsky-Migdal, FLEX, TMA, CPA, KKR, LMTO, heavy-fermion, 3d-transition metals, orbital magnetic moment
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie ; 500 Naturwissenschaften und Mathematik
• Fakultäten: Fakultät für Chemie und Pharmazie
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 20. Dezember 2007
• 1. Bericht­erstatter:in: Ebert, Hubert