Xinguo Ren
LDA+DMFT Investigation of NiO
Supervisor: Prof. Dr. Dieter Vollhardt [Theoretical physics III]
Date of oral examination: 02/16/2006
89 pages, english
In this thesis we give a review of the LDA+DMFT approach in general, and introduce a new scheme of its implementation developed recently. In this scheme, the non-interacting part of the Hamiltonian, expressed in the basis of Wannier functions (WF), is derived from the band structure obtained within the local density approximation (LDA), and on top of it the Coulomb interaction term is explicitly added. The full interacting Hamiltonian is solved by the dynamical-mean field theory (DMFT). This scheme is applied to NiO, and the obtained energy gap, local magnetic moment, and electronic spectrum are in good agreement with experiment. We also discuss the possibility of combining the LDA and DMFT self-consistently, and the formulation of the problem is presented.