Enhanced and tunable Goos-Hänchen shift of reflected light due to Tamm surface plasmons with Dirac semimetals

Abstract

In this paper, enhanced and tunable Goos-Hänchen (GH) shift of reflected light beam at mid-infrared band can be theoretically achieved by using a multilayer structure where a bulk Dirac semimetal (BDS) layer is coated on a distributed bragg reflector (DBR) separated by a spacer layer. This enhanced GH phenomenon results from the local field enhancement owing to the excitation of Tamm surface plasmons at the interface between BDS layer and spacer layer. Numerical calculation shows that the GH shift can be switched from negative to positive by harnessing the bulk conductivity properties of BDS, and can also be actively tuned through the Fermi energy of BDS or by controlling the structural parameters. These enhanced and tunable GH shifts are promising for fabricating BDS-based infrared shift devices and other applications in nanophotonics.