Magneto-plasmonics in graphene-dielectric sandwich.

Bin Hu,Jin Tao,Ying Zhang,Qi Jie Wang

doi:10.1364/oe.22.021727

Abstract

In this paper, dispersion properties and field distributions of surface magneto plasmons (SMPs) in double-layer graphene structures at room temperature are studied. It is found that, the dispersion curves of both symmetric and antisymmetric SMPs modes split into several branches/bands when a magnetic field is applied perpendicularly to the graphene surface. Surprisingly, the lowest energy SMP band has anomalous dependence on the applied magnetic field, different to the other higher bands. In addition, the symmetric and antisymmetric modes can be decoupled if the two graphene layers possess different properties, such as different Fermi energies. Furthermore, electric components of the surface modes which are parallel to the graphene surfaces but perpendicular to the propagation direction (i.e. the transverse-electric mode) are no longer zero caused by the Lorentz force on the free electrons.

Highlights

Plasmonics, a new branch of photonics based on surface plasmons (SPs), has been enormously developed since the discovery of its extraordinary optical transmission property through subwavelength hole arrays [1, 2]
We study the SMPs modes in a graphene-dielectric sandwich (GDS) structure [43,44,45] in which a dielectric layer is placed between two single layer graphene (SLG)
Compared with SLGs, we find that, the SMPs have one symmetric (SM) mode and one anti-symmetric (AM) mode in a GDS structure, which is similar to the SPs in a double-layer graphene [45] in the absence of the magnetic field

Summary

Introduction

Plasmonics, a new branch of photonics based on surface plasmons (SPs), has been enormously developed since the discovery of its extraordinary optical transmission property through subwavelength hole arrays [1, 2]. For a single layer graphene (SLG), it is found that due to the applied magnetic field, the dispersion curve of the SMP mode splits into a series of branches. Compared with SLGs, we find that, the SMPs have one symmetric (SM) mode and one anti-symmetric (AM) mode in a GDS structure, which is similar to the SPs in a double-layer graphene [45] in the absence of the magnetic field. For the reason that the QTE modes are weakly confined, in the following, we only consider the highly confined SMPs modes in a GDS structure

Dispersion relation of SMPs in a GDS structure

Symmetric structures

Asymmetric structures

Conclusion