The objective of this work is the theoretical study of the one band Hubbard model for solids and the introduction of an alternative methodology to circumvent its limitations. To this objective, a Hamiltonian composed of two atoms (the Hubbard dimmer) is introduced and solved analytically. From this Hamiltonian, the atomic Green's functions are obtained for the dimmer, which is used as a seed for a cumulant expansion and to obtain the Green's functions for the lattice. The density of states for several values of interest for the parameters of the problem is calculated, as well as the occupation numbers. As a result of the cumulant expansion, the particle-hole symmetry for high values of the electronic correlation is recovered, the Mott transition is obtained in a consistent way (the electronic correlation is no longer overestimated) and by the analysis of the ocupation numbers of the model for different values of the chemical potential, one can observe near the energy region Eo+U, a Kondo effect region.
Conferencista: Marcos S. Figueira, Instituto de Física de la U. Federal Fluminense (Río de Janeiro, Brasil)
Fecha y hora: lunes 22 de agosto de 2016, 11:00
Lugar: aula 203 (auditorio José Granés) del edificio 405, UN sede Bogotá (ver mapa)
Esta conferencia forma parte del Coloquio de Física UN 2016-II
[Boletín UN Investiga 310, 18 de agosto de 2016]