Magnetic plasmon resonances in nanostructured topological insulators for strongly enhanced light–MoS2 interactions

摘要

a Schematic of a Sb2Te3 TI nanogroove grating with height h, width d, and pitch p underneath monolayer MoS2. The light is incident on the nanostructure with a polarization angle of θ. b TEM high-angle annular dark-field (HAADF) image of a part of a thin Sb2Te3 microflake (inset) on the carbon support film of a copper microgrid. The dotted rectangle denotes the area selected for electron diffraction and high-resolution TEM. The right images are the EDS mapping pictures of the measured part of the Sb2Te3 microflake for determining the spatial distributions of elements Sb and Te. c SAED pattern and HRTEM image (inset) of the Sb2Te3 single crystal. d Measured (circles) and fitted (curves) relative permittivities of the Sb2Te3 single crystal in the UV, visible, and near-infrared ranges. The fitted real and imaginary permittivities are obtained from the ellipsometer software with a layer-on-bulk model (inset) for the Sb2Te3 TI. e, f Real and imaginary permittivities of the conducting surface and insulating bulk.