Plasmonics in topological insulators: Spin-charge separation, the influence of the inversion layer, and phonon-plasmon coupling
arXiv:1706.09403 · doi:10.1021/acsphotonics.7b00524
Abstract
We demonstrate via three examples that topological insulators (TI) offer a new platform for plasmonics. First, we show that the collective excitations of a thin slab of a TI display spin-charge separation. This gives rise to purely charge-like optical and purely spin-like acoustic plasmons, respectively. Second, we argue that the depletion layer mixes Dirac and Schrödinger electrons which can lead to novel features such as high modulation depths and interband plasmons. The analysis is based on an extension of the usual formula for optical plasmons that depends on the slab width and on the dielectric constant of the TI. Third, we discuss the coupling of the TI surface phonons to the plasmons and find strong hybridisation especially for samples with large slab widths.
37 pages, 7 figures
References in corpus (15)
- Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
- Dielectric function, screening, and plasmons in 2D graphene
- Dynamical polarization of graphene at finite doping
- Realization of a High Mobility Dual-gated Graphene Field Effect Transistor with Al2O3 Dielectric
- Mid-infrared plasmons in scaled graphene nanostructures
- Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
- Drude weight, plasmon dispersion, and a.c. conductivity in doped graphene sheets
- Quasi-flat plasmonic bands in twisted bilayer graphene
- Coulomb drag between massless and massive fermions
- Plasmons in layered structures including graphene
- Dielectric function, screening, and plasmons of graphene in the presence of spin-orbit interactions
- Universal features of the optical properties of ultrathin plasmonic films
- Dynamical current-current correlation of the hexagonal lattice and graphene
- Surface plasmon polaritons in topological insulator
- Screening properties and plasmons of Hg(Cd)Te quantum wells