Seminarium "Teoria i Modelowanie Nanostruktur"

Friedel oscillations(FO) are quantum mechanical phenomenon observed in metals in presence of charged impurities. FO in the Fermi liquid phase, Mott insulating phase, and at the Mott transition is studied in one and two dimensional lattice models. Electronic correlations are accounted for using different models, approximations, and by solving the dynamical mean-field theory equations, using numerical renormalization group for infinite homogeneous system. Different types of impurity potentials are considered. The problem is solved numerically by exact diagonalization. We observe that in the metallic phase the amplitudes of FO are damped with increasing the interactions while the period remains unchanged. FO almost disappear close to the Mott transition and completely beyond it. An additional bound state is observed in the spectral function at the impurity site which splits along with the sub-bands on increasing the interactions.