Chemical sensing with graphene: A quantum field theory perspective

TL;DR

This paper presents a theoretical model showing how adsorbed polar molecules affect graphene's optical conductivity, providing insights for chemical sensor development using a quantum field theory approach.

Contribution

It extends the continuum model of graphene to include next-nearest neighbor effects and derives an analytical expression linking molecular adsorption to conductivity changes.

Findings

Conductivity depends on renormalized quasiparticle parameters influenced by molecular surface concentration.

Provides an analytical framework for graphene-based chemical sensors.

Extends previous models by including next-nearest neighbor interactions.

Abstract

We studied theoretically the effect of a low concentration of adsorbed polar molecules on the optical conductivity of graphene, within the Kubo linear response approximation. Our analysis is based on a continuum model approximation that includes up to next to nearest neighbors in the pristine graphene effective Hamiltonian, thus extending the field-theoretical analysis developed in Refs.[1,2]. Our results show that the conductivity can be expressed in terms of renormalized quasiparticle parameters $\tilde{v}_F$, $\tilde{M}$ and $\tilde{\mu}$ that include the effect of the molecular surface concentration $n_{dip}$ and dipolar moment $\boldsymbol{\mathcal{P}}$, thus providing an analytical model for a graphene-based chemical sensor.