Dimensional and temperature dependence of metal-insulator transition in correlated and disordered systems

We study the dimensional dependence of the interplay between correlation and disorder in two dimensions at half-filling using the 2D t-t' disordered Hubbard model with deterministic disorder both at zero and finite temperatures. Inclusion of t' without disorder leads to a metallic phase at half-filling below a certain critical value of U. Above this critical value U-c correlation favours an antiferromagnetic phase. Since disorder leads to double occupancy over the lower-energy site, the competition between Hubbard U and disorder leads to the emergence of a metallic phase, which can be quantified by the calculation of Kubo conductivity, gap at half-filling, density of states, spin order parameter, inverse participation ratio (IPR) and bandwidth. We have studied the effect of disorder on the system in a very novel way through a deterministic disorder which follows a Fibonacci sequence. The behaviour of different quantities shows interesting features on going from a two-to quasi-one-dimensional system. Copyright (C) EPLA, 2009