Optical properties of two-dimensional Dirac–Weyl materials with a flatband

Abstract

The emergence of a flatband in Dirac–Weyl materials offers new possibilities for electronic transitions, leading to stronger interaction with light. As a result, the optical conductivity can be significantly enhanced in these flatband materials as compared with graphene, making them potentially better candidates for optical sensing and modulation. Recently, a comprehensive theory for the optical conductivity of a spectrum of flatband Dirac–Weyl materials has been developed, with explicit formulas for both the real and imaginary parts of the conductivity derived through two independent approaches. This Perspective offers a review of the development. An understanding of the optical properties of the flatband Dirac–Weyl materials paves the way for optical device applications in the terahertz-frequency domain.