Complexidade e Propriedades Electrónicas | Complexity and Electronic Properties : [202] Estatísticas


Members of CEP, informally organized in the investigation unit “Materials and Systems Strongly Correlated and Limiting States of Matter”, have worked in the field of strongly correlated systems using two different approaches:

(i) in quasi-unidimensional physical systems, that can be studied using equations that have exact mathematical solutions, the results of the calculation of the spectral properties of one particle can be directly compared with experimental data obtained from such techniques as, for example, Angular Resolution Photoemission Spectroscopy (ARPES). For the first time, members of the group reported complete agreement between theoretical predictions and experimental data in the study of the spectral lines of one such system (TTF-TCNQ).

(ii) in bi-dimensional systems with honeycomb lattices there are no exact mathematical solutions describing their electronic and magnetic properties. Therefore, perturbative methods to solve these many-body problems are required. For the honeycomb lattice, members of the group proved in a rigorous manner that a magnetic excitation that had been previously proposed, based on approximate calculation methods, could not exist. The magnetic phase diagram at absolute zero for electrons in that lattice was also studied. Antiferromagnetic excitations for the case of a half-filled band were calculated, and the renormalization of the antiferromagnetic magnetization was performed using spin waves.

Other members of CEP, informally organized in the investigation unit “Thin films for electronics, colloids and nanotechnologies”, studied the kinetics of film growth for several thin-film deposition models. Other kinetic studies included heterogeneous reactions on catalysts and deposition of colloids on collectors.