ubc Charge degrees of freedom on the kagome lattice 2011-09-22 [Electronic ed.] prv Universitätsbibliothek Chemnitz Universitätsbibliothek Chemnitz, Chemnitz Naturwissenschaften Physik female Sydney 0 and t < 0. Exact diagonalization calculations are found to be consistent with the predictions of the effective model. Further calculations confirm that the sign of t is rendered inconsequential due to the gauge invariance for g in the regime |t| << V . The charge-order melting metal-insulator transition is studied through density-matrix renormalization group calculations. The opening of the energy gap is found to differ for the two signs of t, reflecting the difference in the band structure at the Fermi level in each case. The qualitative nature of transition in each case is discussed. As a step towards a realization of the model in experiment, density-density correlation functions are introduced and such a calculation is shown for the plaquette phase for the effective model Hamiltonian at 1/3 filling in the absence of defects. Finally, the open problem of statistics of the fractional charges is discussed.]]> 530 Physik, Festkörper Festkörper, Physik Strongly correlated electron systems Lattice fermion models Metal-insulator transitions urn:nbn:de:bsz:ch1-qucosa-71860 Technischen Universitaet Chemnitz dgg Technischen Universitaet Chemnitz, Chemnitz Aroon O'Brien 1985-09-01 aut Michael Schreiber Prof. Dr. dgs rev Peter Fulde Prof. Dr. dgs rev eng 2010-10-18 2010-12-20 born digital Ladungsfreiheitsgrade auf dem Kagome Gitter Aroon O'Brien +49 351 871 1124 aroonobrien@hotmail.com doctoral_thesis