arXiv subjects

J. M. V. P. Lopes

Publications and source records attributed to J. M. V. P. Lopes.

2 recordsLinked to original sources

arXiv2021

Basis-Independent Spectral Methods for Non-linear Optical Response in Arbitrary Tight-binding Models

In this paper, we developed a basis-independent perturbative method for calculating the non-linear optical response of arbitrary non-interacting tight-binding models. Our method is based on the non-equilibrium Keldysh formalism and allows an efficient numerical implementation within the framework of the Kernel Polynomial Method for systems which are not required to be translation-invariant. Some proof-of-concept results of the second-order optical conductivity are presented for the special case of gapped graphene with vacancies and an on-site Anderson disordered potential.

cond-mat.other↗

arXiv1998

Electronic spectrum and hopping conductivity in highly doped lattice systems

A model of strongly disordered lattice system with long-range Coulomb interactions between localized charge carriers has been considered. The total electronic energy is characterized by the presence of multiple metastable minima (including the true ground state), and different types of excitation spectra over these minima. A numeric procedure, accounting for all many-body correlations in finite size samples, confirms the existence of Coulomb gap in the single-particle spectrum and also provides corrections to the known mean-field theory results, as asymmetry of the gap at non-half-filling, vanishing density of low energy pair excitations, modified temperature exponent for hopping conductivity.

cond-mat.str-el↗