Optical properties of biased bilayer graphene due to gap parameter effects

TL;DR

This paper investigates how bias voltage, gap parameter, and stacking type influence the optical conductivity of bilayer graphene at finite temperature, revealing characteristic peaks and their dependence on these parameters.

Contribution

It presents a detailed analysis of the optical conductivity of biased bilayer graphene considering gap effects and stacking types using a Green's function approach.

Findings

Optical conductivity exhibits a frequency-dependent peak influenced by temperature and bias voltage.

The peak in optical conductivity shifts to higher frequencies with increasing gap parameter.

The study provides insights into the optical response variations in bilayer graphene under different conditions.

Abstract

We address the optical conductivity of undoped bilayer graphene in the presence of a finite bias voltage at finite temperature. The effects of gap parameter and stacking type on optical conductivity are discussed in the context of tight binding model Hamiltonian. Green's function approach has been implemented to find the behavior of optical conductivity of bilayer graphene within linear response theory. We have found the frequency dependence of optical conductivity for different values of gap parameter and bias voltage. Also the dependence of optical conductivity on the temperature has been investigated in details. A peak appears in the plot of optical conductivity versus frequency for different values of temperatures and bias voltage. Furthermore we find the frequency position of broad peak in optical conductivity goes to higher values with increase of gap parameter for both bernal and simple stacked bilayer graphenes.