No 5 (2024)
Interaction of electromagnetic field with materials
Surface permittivity of ultrathin films
Abstract
Slabs of width much smaller than the wavelength are of high importance in many areas of electrodynamics. Such slabs are widely used as antireflection films, absorbers, catalysts and functional coatings. For treating optical systems involving ultrathin films, it is crucial to propose their proper description considering only necessary parameters. We provide a theoretical characterization of an arbitrary inhomogeneous ultrathin slab using surface permittivity , which does not require knowledge of the slab thickness. Moreover, we show that is a scalar complex value, i.e. the proposed approach does not include consideration of the anisotropic properties of the slab. We process experimentally measured ellipsometry spectra to confirm the reliability of proposed method. We also show that the description of the slab using does not significantly increase the discrepancy comparing to the description through a homogeneous layer of finite thickness, at the same time reducing the number of model parameters making it more convenient to use. In addition, we find a relation between the parameter and the resistance per square widely used in the description of thin conducting layers.
4-13
Topics on interaction of an electromagnetic field with materials
Scattering due to edge imperfections in topological insulators in the uniform magnetic field
Abstract
We study the scattering of edge excitations of 2D topological insulator (TI) in the uniform external magnetic field due to edge imperfections, ubiquitous in realistic 2D TIs. Our previous study shows the possible existence of oscillations of reflection amplitude in a weak magnetic field. In this paper, we address yet another general class of edge deformation profiles and also discover quantum oscillations of the scattering coefficient in one more general situation of low momentum carriers. The semiclassical Pokrovsky-Khalatnikov approach is used to obtain reflection coefficient with pre-exponential accuracy.
14-24
Plasmon zebra resonances and nanopainting
Abstract
We investigate metal-dielectric metasurfaces composed from periodic metal nanostrips deposited on a dielectric substrate. The metasurface can be termed as plasmon zebra (PZ). The metasurface operates as a set of open plasmon resonators. The theory of plasmon, excited in the open, interconnect resonators, is developed. The large local electromagnetic field is predicted for optical frequencies when plasmon is exited. The reflectance of PZ is much enhanced at the frequency of plasmon resonance and PZ ascribe the color corresponding to the resonance frequency. We propose PZ as simplest but easy tuning plasmon painting.
25-36