Optical properties of graphene

TL;DR

This paper analyzes the optical properties of graphene, focusing on how reflectance and transmittance depend on frequency, temperature, and carrier density, highlighting the role of interband electron transitions and conductivity behavior.

Contribution

It provides a detailed theoretical analysis of graphene's optical response, emphasizing the universal conductivity and divergence phenomena at interband transition thresholds.

Findings

Real part of conductivity is universal at low temperatures.

Imaginary part diverges logarithmically at interband thresholds.

Optical properties depend on frequency, temperature, and carrier density.

Abstract

Reflectance and transmittance of graphene in the optical region are analyzed as a function of frequency, temperature, and carrier density. We show that the optical graphene properties are determined by the direct interband electron transitions. The real part of the dynamic conductivity in doped graphene at low temperatures takes the universal constant value, whereas the imaginary part is logarithmically divergent at the threshold of interband transitions.