Electron Transport Through Ag-Silicene-Ag Junctions

TL;DR

This paper develops a hybrid quantum-classical framework to analyze electron transport in Ag-silicene-Ag junctions, providing detailed calculations of transmission, reflection, and resistance, revealing lower resistances than traditional models.

Contribution

It introduces a novel theoretical approach combining NEGF, scattering, and Boltzmann methods to study metal-silicene junction transport properties.

Findings

Resistances are approximately 0.08 Ω·fm for monolayer silicene junctions.

Resistances are approximately 0.3 Ω·fm for bilayer silicene junctions.

Resistances are significantly lower than Sharvin estimates from Landauer formalism.

Abstract

For several years the electronic structure properties of the novel two-dimensional system silicene have been studied extensively. Electron transport across metal-silicence junctions, however, remains relatively unexplored. To address this issue, we developed and implemented a theoretical framework that utilizes the tight-binding Fisher-Lee relation to span non-equilibrium Green's function (NEGF) techniques, the scattering method, and semiclassical Boltzmann transport theory. Within this hybrid quantum-classical, two-scale framework, we calculated transmission and reflection coefficients of monolayer and bilayer Ag-silicene-Ag junctions using the NEGF method in conjunction with density functional theory; derived and calculated the group velocities; and computed resistance using the semi-classical Boltzmann equation. We found that resistances of these junctions are $\sim${}$ 0.08 \fom$ for monolayer silicene junctions and $\sim${}$ 0.3 \fom$ for bilayer ones, factors of $\sim$8 and $\sim$2, respectively, smaller than Sharvin resistances estimated via the Landauer formalism.