Symmetric and asymmetric charge transport in interacting asymmetric quantum impurities

TL;DR

This paper investigates charge transport in asymmetric quantum impurity models, revealing symmetric behavior with linear dispersion and rectification effects with nonlinear dispersion, highlighting the impact of lead dispersion on diode-like behavior.

Contribution

It provides exact solutions for linear dispersion and explores nonlinear effects, showing how lead dispersion influences rectification in quantum impurity systems.

Findings

Linear dispersion leads to symmetric current-voltage characteristics.

Nonlinear dispersion induces rectification in asymmetric junctions.

Perfect junctions with interactions do not exhibit rectification.

Abstract

We study steady-state charge transfer across an interacting resonance-level model connected asymmetrically to two leads. For a linear energy dispersion relation of the leads, we calculate current-voltage characteristics of the model exactly employing the scattering Bethe-Ansatz of Mehta-Andrei and find symmetric transport showing the absence of diode effect. Next we study a lattice version of this model with a nonlinear dispersion for the leads using the Lippmann-Schwinger scattering theory. We find that the inclusion of nonlinearity in the leads' dispersion causes rectification for asymmetric junctions but does not rectify for asymmetric interactions and perfect junctions. The model in the latter case can be mapped into a model of a single noninteracting electron in higher dimensions.