Speaker
Gayanath Fernando
Description
Abstract: Using exact diagonalization (ED) and variational
cluster
approach (VCA), it is shown that the repulsive Hubbard clusters
having square geometry undergo electronic phase separation away
from half filling in the single band Hubbard. This is strictly a
correlation driven effect due to level crossings which occurs
below a certain value of the on-site Coulomb repulsion and
yields
paired states around this filling. VCA results demonstrate that
this phase separation survives even when long range effects are
taken into account. In the honeycomb geometry, ED and VCA show
that such a phase separation is absent.
