Sensitive chemical potential sensor based on graphene hyperbolic metamaterials

We have studied the anisotropic dispersion properties of hyperbolic metamaterials having a graphene/dielectric periodic structure and proposed a sensitive chemical potential sensor. It is found that the equifrequency contour of the structure will transit from an ellipse to a hyperbola as the chemical potential of graphene increases over a certain critical value. Interestingly, as the chemical potential increases close to the critical value, the transmittance varies very sensitively and nearly linearly in a wide range but with a small change of chemical potential. Based on these unique properties, we design a sensitive chemical potential sensor with advantages of fast response and high sensitivity simultaneously. Additionally, the measurement range of chemical potential can be expanded by adjusting the working frequency conveniently. These results have potential in many application fields such as beam control and sensing.