Effect of vertex corrections on the longitudinal transport through multilayered nanostructures: Exact dynamical mean-field theory approach applied to the inhomogeneous Falicov-Kimball model

TL;DR

This study uses inhomogeneous dynamical mean-field theory to evaluate how vertex corrections influence charge transport in multilayered nanostructures, revealing small but notable effects that depend on device thickness and metallicity.

Contribution

It provides an exact calculation of vertex corrections on transport in multilayered devices using the Falicov-Kimball model, highlighting their limited but variable impact.

Findings

Vertex corrections cause a small reduction in resistance-area product.

Effects of vertex corrections saturate with increasing barrier thickness.

More metallic and thinner devices experience larger relative effects.

Abstract

Inhomogeneous dynamical mean-field theory is employed to calculate the vertex-corrected electronic charge transport for multilayered devices composed of semi-infinite metallic lead layers coupled through a strongly correlated material barrier region. The barrier region can be tuned from a metal to a Mott insulator through adjusting the interaction strength and the particle filling. We use the Falicov-Kimball model to describe the barrier region because an exact expression for the vertex corrections is known, allowing us to determine their effect on transport. The dc conductivity is calculated and we find the effects of the vertex corrections are relatively small, manifesting themselves in a small reduction in the resistance-area product. This reduction saturates in absolute magnitude as the barrier layer becomes thick, as expected due to the vanishing nature of the vertex corrections in bulk. The vertex corrections have a larger relative effect on the resistance-area product for more metallic and thinner devices.