Enhancing sensitivity to ambient refractive index with tunable f...

Refractive index (RI) sensing helps to identify biomolecules and chemicals in the mid-infrared range for drug discovery, bioengineering, and environmental monitoring. In this paper, we numerically demonstrate an electrically tunable RI sensor with ultrahigh sensitivity using a three-layer graphene nanoribbon array separated by hexagonal boron nitride (hBN). Unlike the weak resonance in single-layer graphene nanoribbons, a much stronger plasmon resonance featuring a higher-quality factor can be e