Superfluidity and collective properties of excitonic polaritons in gapped graphene in a microcavity

We predict the formation and superfluidity of polaritons in an optical microcavity formed by excitons in gapped graphene embedded there and microcavity photons. The Rabi splitting related to the creation of an exciton in a graphene layer in the presence of the band gap is obtained. It is demonstrated that the Rabi splitting decreases when the energy gap increases, while the larger value of the dielectric constant of the microcavity gives a smaller value for the Rabi splitting. The analysis of collective excitations as well as the sound velocity is presented. We show that the superfluid density $n_s$ and temperature of the Kosterlitz-Thouless phase transition $T_c$ are decreasing functions of the energy gap.

Figure 1

The dependence of the parameter $r_0$ on the gap energy $\delta$.

Figure 2

The dependence of $U$ on the gap energy $\delta$.

Figure 3

The dependence of the Rabi splitting $\left|\hslash {\Omega }_R\right|$ on the gap energy $\delta$ for microcavities with the different dielectric constants ${\varepsilon }_{\mathrm{cav}}$.

Figure 4

The dependence of the Kosterlitz-Thouless transition temperature $T_c$ on the gap energy $\delta$ for the different polariton densities for a GaAs microcavity.

Figure 5

The dependence of the Kosterlitz-Thouless transition temperature $T_c$ on the gap energy $\delta$ for the different polariton densities for a CuBr microcavity.

Figure 6

The dependence of the Kosterlitz-Thouless transition temperature $T_c$ on the gap energy $\delta$ for microcavities with the different dielectric constants ${\varepsilon }_{\mathrm{cav}}$.