The influence of a conducting surface on the conductivity of graphene

TL;DR

This paper studies how a grounded conducting surface affects the electrical conductivities of graphene, revealing that proximity enhances longitudinal conductivity but causes optical conductivity to peak then decrease, offering a new control method.

Contribution

It introduces a Pseudo-Quantum Electrodynamics approach to analyze the impact of a conducting surface on graphene's conductivities, providing novel insights into their dependence on distance.

Findings

Longitudinal conductivity increases as the conducting surface approaches.

Optical conductivity peaks at a certain proximity and then decreases.

Results recover known behavior when the surface is far away.

Abstract

In the present paper, using Pseudo-Quantum Electrodynamics to describe the interaction between electrons in graphene, we investigate the longitudinal and optical conductivities of a neutral graphene sheet near a grounded perfectly conducting surface, with calculations up to 2-loop perturbation order. We show that the longitudinal conductivity increases as we bring the conducting surface closer to the graphene sheet. On the other hand, although the optical conductivity initially increases with the proximity of the plate, it reaches a maximum value, tending, afterwards, to the minimal conductivity in the ideal limit of no separation between graphene and the conducting surface. We recover the correspondent results in the literature when the distance to the plate tends to infinity. Our results may be useful as an alternative way to control the longitudinal and optical conductivities of graphene.