Influence of rings on the electronic structure of lattices with topological defects

Abstract

AbstractThe influence of rings on the electronic structure of open and closed lattices, like the Bethe and Husimi lattices, respectively, is studied. In both lattices topological defects are introduced changing, in alternating form, the number of nearest neighbors on each site. In the Bethe lattice with or without topological defects the local density of states has the symmetry of a central ring, but topological defects generate a gap in the electronic structure and some bound states in between. In the Husimi model formed with rings of two different numbers of sides, it is found that the electronic bands are symmetrical, if and only if, combinations of rings with even number of sides, independent of the presence of topological defects, are considered. In addition, gaps appear when alternating topological defects are introduced.