Nonlinear conductance and negative differential resistance of nanowires: A combined model and ab-initio theory

The main goal of the proposal is to explore possible occurrence of negative differential resistance in nanowires containing or attached to localized perturbations like impurities or nanocontacts. To this end we will develop in a first step a framework based on many-body theory. This methodology is then adopted in an ab-initio calculational scheme based on density functional theory and a Green’s function method for dealing with the impurity problem. Transport calculations are then performed using the non-equilibrium Green’s function that captures features inherent at finite applied bias. The method will be applied to metallic wires (Fe, Co, Ni) and semiconducting wires (ZnO).