Nonlinear I-V Characteristics of a Mesoscopic Conductor

TL;DR

This paper develops a comprehensive theoretical framework using nonequilibrium Green's functions to analyze nonlinear DC transport in mesoscopic conductors, accounting for gauge invariance and electron interactions.

Contribution

It introduces a gauge-invariant theoretical formulation for nonlinear transport in mesoscopic systems, with explicit treatment of exchange and correlation effects.

Findings

The theory predicts current-voltage characteristics accurately.

Analytical I-V curves are derived for specific cases.

Comparison with scattering matrix theory validates the approach.

Abstract

We present a general theoretical formulation, based on nonequilibrium Green's functions, for nonlinear DC transport in multi-probe mesoscopic conductors. The theory is gauge invariant and is useful for the predictions of current-voltage characteristics and the nonequilibrium charge pile-ups inside the conductor. We have provided a detailed comparison between the gauge invariant scattering matrix theory and our theory. We have also given several examples where the I-V curve can be obtained analytically. The effects of exchange and correlation have been considered explicitly.