# Far-infrared Tamm polaritons in a microcavity with incorporated graphene sheet

## TL;DR

This paper explores the formation and properties of far-infrared Tamm polaritons at a GaAs-Bragg mirror interface, including the effects of a graphene layer, revealing their dispersion and existence conditions.

## Contribution

It introduces the concept of far-infrared Tamm polaritons in a GaAs-based structure with a Bragg reflector and analyzes the impact of incorporating a graphene layer.

## Key findings

- Dispersion relation of FIR Tamm polaritons in GaAs-Bragg structures
- Existence window for Tamm polaritons in the FIR range
- Effect of a graphene layer on Tamm polariton properties

## Abstract

Tamm polaritons (TPs) are formed at the interface between two semi-infinite periodic dielectric structures (Bragg mirrors) or other reflectors. Contrary to usual surface polaritons, TPs exist inside the "light cone", even though their amplitude also decreases exponentially with the distance from the interface as it is characteristic of evanescent waves. They couple to elementary excitations in the materials or structures that form the interface, such as metal plasmons or semiconductor excitons. Here we discuss the formation of TPs in the far-infrared (FIR) spectral range, in the optical-phonon reststrahlen band of a polar semiconductor such as GaAs, with a Bragg reflector (BR) as the second mirror. Their dispersion relation and the frequency window for the TP existence are discussed for a GaAs-BR interface. Structures containing a gap between the two reflectors are also considered. Further investigation is performed on a structure containing a layer of graphene between the two reflectors.