Electronic correlations in the Hubbard model on the Kagome lattice

Abstract

The aim of this thesis is the investigation of electronic correlations in the intermediate region between the metallic and insulating phase of the frustrated Kagome lattice. Most previous studies address the ground state of the Heisenberg model on the Kagome lattice, and therefore only the purely insulating phase. However, we go a step further by studying the Hubbard model on the Kagome lattice and thus including metallic contributions. We solve the Hubbard model with the determinant quantum Monte Carlo (DQMC) method and compare to results of the dynamical mean field theory (DMFT). First we study the half-filled system across the range of the Mott-Hubbard metal-insulator transition, and then the electron doped system, where the chemical potential is in the center of the flat band. In various post-processing steps we calculate the k-integrated spectral functions, the k-resolved spectral functions, the equal-time magnetic structure factors and the dynamic magnetic structure factors.