Theoretical demonstration of surface plasmon polaritons in plasma/vacuum interface in GHz frequency

Negative permittivity of the material may lead to the enhanced radiation of an antenna embedded in a finite plasma, which suggests a potential way to solve blackout problem in space technology. However, the enhanced radiation phenomenon is still lack of strict theoretical investigations of surface plasmon polaritons (SPPs) in plasma in GHz frequency. In this paper, we demonstrate the SPPs excited at a plasma/vacuum interface in GHz frequency by the consistency of the simulated and theoretical results. With SPPs, plasma layer thicker than skin depth can be penetrated with w < w_p, which is a complement of wave propagation theory in plasma. We also discuss the influences of thickness d, collision frequency Γ, and different plasma frequencies on SPPs. For plasma frequencies with large difference, common numerical methods have difficulties in result comparison under the same mesh size because of the computer capacity and memory. The analytical multilayer method used in the paper does not need to generate mesh, so the studies of plasma frequencies with large difference can be carried out. The simulation shows that the SPPs can be excited for an arbitrary plasma frequency. We believe the study will be beneficial for the problem of wave propagation in plasma science and technology.