Propagation of Surface Plasmon Polaritons in Thin Films of Topological Insulators

摘要

The propagation of surface plasmon polaritons in thin films of topologicalinsulators is studied. The materials considered are second generation threedimensional topological insulators Bi$_2$Se$_3$, Bi$_2$Te$_3$, andSb$_2$Te$_3$. Dispersion relations and propagation lengths are estimatednumerically, taking into account the variation of bulk dielectric functions oftopological insulators as well as substrate using the Drude-Lorentz model. Keyfactors affecting propagation length are identified and ways to modify thedispersion relations are suggested. The explanation of the apparent discrepancybetween the experimental data for Bi$_2$Se$_3$ and theory is proposed.