Magneto-tunable terahertz absorption in single-layer graphene: A general approach

TL;DR

This paper presents a method to achieve tunable terahertz absorption in single-layer graphene by applying a magnetic field, enabling control over anisotropic absorption and potential applications in THz technology.

Contribution

The study derives generalized Fresnel coefficients for graphene under magnetic fields and demonstrates temperature-dependent absorption features, advancing tunable THz device design.

Findings

High anisotropic absorption achievable with specific scattering angles

Absorption correlates with surface optical conductivity under magnetic field

Stepwise absorption emerges at low temperatures

Abstract

Terahertz (THz) anisotropic absorption in graphene could be significantly modified upon applying a static magnetic field on its ultra-fast 2D Dirac electrons. In general, by deriving the generalized Fresnel coefficients for monolayer graphene under applied magnetic field, relatively high anisotropic absorption for the incoming linearly polarized light with specific scattering angles could be achieved. We also prove that the light absorption of monolayer graphene corresponds well to its surface optical conductivity in the presence of a static magnetic field. Moreover, the temperature-dependent conductivity of graphene makes it possible to show that a step by step absorption feature would emerge at very low temperatures. We believe that these properties may be considered to be used in novel graphene-based THz application.