Regensburg 2004 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 28: FV-internes Symposium ”Theoretical Modeling of Materials with Correlated Electrons”
TT 28.5: Fachvortrag
Donnerstag, 11. März 2004, 15:40–16:05, H20
Multi-Band Gutzwiller Method for Transition metals and Compounds: Magnetism, Fermi Surfaces and Spin-Orbit Coupling — •Werner Weber1, Jörg Bünemann2, and Florian Gebhard2 — 1Institu für Physik, Universität Dortmund — 2Fachbereich Physik, Philipps Universität Marburg
The multi-band Gutzwiller method is used to calculate ground state properties and quasi-particle energy bands of magnetic transition metals and compounds. Our scheme utilizes single-particle model Hamiltonians with an s, p, and d spin orbital basis, obtained from density functional theory studies. For cubic, ferromagnetic Nickel our results even correctly reproduce details of the quasi particle bands near the Fermi surface. In the case of low crystal symmetry and/or of a large orbital basis, the hopping reduction factors q(σ,σ′)of the effective single particle Hamiltonian have a matrix form in the space of the spin orbitals σ. Furthermore, additional variational parameters appear, which act on the eigenvectors of the atomic multiplet states. Incorporation of spin-orbit coupling for Nickel results, via the off-diagonal q(σ,σ′), in spin-flip hopping terms of the effective Hamiltonian. These terms considerably enhance the value of the orbital magnetic moment over the Hartree-Fock limit, so that good agreement with experiment is achieved.
16:05 Pause