Dynamical corrections to the DFT-LDA electron conductance in nanoscale systems

TL;DR

This paper derives an analytical correction to the conductance of nanoscale systems using time-dependent density functional theory, highlighting the importance of dynamical exchange-correlation effects especially in molecular junctions.

Contribution

It introduces a new analytical expression for dynamical exchange-correlation corrections to conductance within TDDFT, emphasizing non-linear density gradient effects.

Findings

Correction depends non-linearly on electron density gradient

More significant in molecular junctions than quantum point contacts

Numerical examples illustrate the correction's impact

Abstract

Using time-dependent current-density functional theory, we derive analytically the dynamical exchange-correlation correction to the DC conductance of nanoscale junctions. The correction pertains to the conductance calculated in the zero-frequency limit of time-dependent density-functional theory within the adiabatic local-density approximation. In particular, we show that in linear response the correction depends non-linearly on the gradient of the electron density; thus, it is more pronounced for molecular junctions than for quantum point contacts. We provide specific numerical examples to illustrate these findings.