Strong terahertz response in bilayer graphene nanoribbons

TL;DR

This paper identifies a specific class of bilayer graphene nanoribbons with exceptionally strong terahertz and far-infrared optical responses, surpassing the universal conductance of graphene sheets, which could advance electronic and photonic applications.

Contribution

It introduces a new class of bilayer graphene nanoribbons with enhanced terahertz response due to their unique energy dispersion properties.

Findings

Peak conductance is about 100 times higher than universal conductance.

The terahertz active class has one-dimensional massless Dirac Fermion dispersion.

Results enable potential applications in electronics and photonics.

Abstract

We reveal that there exists a class of graphene structures (a sub-class of bilayer graphene nanoribbons) which has unusually strong optical response in the terahertz (THz) and far infrared (FIR) regime. The peak conductance of terahertz/FIR active bilayer ribbons is around two orders of magnitude higher than the universal conductance of $e^2/4\hbar$ observed in graphene sheets. The criterion for the terahertz/FIR active sub-class is a bilayer graphene nanoribbon with one-dimensional massless Dirac Fermion energy dispersion near the $\Gamma$ point. Our results overcome a significant obstacle that hinders potential application of graphene in electronics and photonics.