arXiv subjects

Viktoriia Babicheva

Publications and source records attributed to Viktoriia Babicheva.

4 recordsLinked to original sources

arXiv2024

Optical Chiral Response of MXene Nanoantenna Lattice

The chiral response from nanoantennas is useful for enabling advanced applications in areas such as optical communication, sensing, and imaging, due to its ability to selectively interact with circularly polarized light. Lattice resonances in periodic nanoantenna arrays can enhance the optical response of the nanostructure and facilitate stronger light-matter interaction. We design a nanoantenna array made of highly conductive layered MXene material, capitalizing on the lattice's unique properties to control the optical response. We demonstrate the chiral properties of this periodic array of MXene nanoantennas, and these properties are defined by the lattice periodicity. Despite being a lossy optical material in the near-infrared range, the lattice arrangement of MXene facilitates the excitation of stronger resonances, thereby enhancing its overall response. Utilizing chiral periodic lattices presents a promising avenue to significantly enhance the chiral response in lossy materials, including but not limited to MXene, transition metal dichalcogenides, and lossy metals.

physics.optics↗

arXiv2018

Lattice Kerker effect in the hexagonal boron nitride antenna array

Subwavelength particles with hyperbolic light dispersion in the constituent medium are a promising alternative to plasmonic, high-refractive-index dielectric, and semiconductor structures in the practical realization of nanoscale optical elements. Hexagonal boron nitride (hBN) is a layered van der Waals material with natural hyperbolic properties and low-loss phonon-polaritons at the same time. In this work, we consider multipole excitations and antennas properties of hBN particles with an emphasis on the periodic arrangement and collective array modes. We analyze excitation of lattice resonances in the antenna array and effect of resonance shifts and overlap with other multipoles supported by particles in the lattice. A decrease of reflectance from the array is achieved with appropriate lattice spacing (periods) where the electric and magnetic multipoles overlap, and the resonance oscillations are in phase and comparable in magnitude. We theoretical demonstrate that generalized Kerker condition is satisfied in this case, and hBN antennas in the array efficiently scatter light in the predominantly forward direction resulting in near-zero reflectance. The resonant lattice Kerker effect with hyperbolic-medium antennas can be applied in developing metasurfaces based on hBN resonators for mid-infrared photonics.

physics.optics↗

arXiv2017

Reflection compensation mediated by electric and magnetic resonances of all-dielectric metasurfaces

All-dielectric nanostructures have recently emerged as a promising alternative to plasmonic devices, as they also possess pronounced electric and magnetic resonances and allow effective light manipulation. In this work, we study optical properties of a composite structure that consists of a silicon nanoparticle array (metasurface) and high-index substrate aiming at clarifying the role of substrate on reflective properties of the nanoparticles. We develop a simple semi-analytical model that describes interference of separate contributions from nanoparticle array and the bare substrate to the total reflection. Applying this model, we show that matching the magnitudes and setting the π-phase difference of the electric and magnetic dipole moments induced in nanoparticles, one can obtain a suppression of reflection from the substrate coated with metasurface. We perform numerical simulations of sphere and disk nanoparticle arrays for different permittivities of the substrate. We find full agreement with the semi-analytical results, which means that the uncoupled-element model adequately describes nanostructure reflective properties, despite the effects of induced bi-anisotropy. The model explains the features of the reflectance spectrum, such as a number of dips and their spectral positions, and show why it may not coincide with the spectral positions of Mie resonances of the single nanoparticles forming the system. We also address practical aspects of the antireflective device engineering: we show that the uncoupled-element model is applicable to the structures on top of silicon substrates, including lithographically defined nanopillars. The reflectance suppression from nanoparticle array on top of the silicon substrate can be achieved in a broad spectral range with disordered nanoparticle array and for a wide range of incidence angles.

physics.optics↗

arXiv2015

Nanoscopy Reveals Metallic Black Phosphorus

Layered and two-dimensional (2D) materials such as graphene, boron nitride, transition metal dichalcogenides(TMDCs), and black phosphorus (BP) have intriguing fundamental physical properties and bear promise of numerous important applications in electronics and optics. Of them, BP is a novel 2D material that has been theoretically predicted to acquire plasmonic behavior for frequencies below ~0.4 eV when highly doped. The electronic properties of BP are unique due to an anisotropic structure, which could strongly influence collective electronic excitations. Advantages of BP as a material for nanoelectronics and nanooptics are due to the fact that, in contrast to metals, the free carrier density in it can be dynamically controlled by electrostatic gating, which has been demonstrated by its use in field-effect transistors. Despite all the interest that BP attracts, near-field and plasmonic properties of BP have not yet been investigated experimentally. Here we report the first observation of nanoscopic near-field properties of BP. We have discovered near field patterns of outside bright fringes and high surface polarizability of nanofilm BP consistent with its surface-metallic, plasmonic behavior at mid-infrared (mid-IR) frequencies. This behavior is highly frequency-dispersive, disappearing above frequency, ω =1070 cm-1, which allowed us to estimate the plasma frequency and carrier density. We have also observed similar behavior in other 2D semiconductors such as TMDCs but not in 2D insulators such as boron nitride. This new phenomenon is attributed to surface charging of the semiconductor nanofilms. This discovery opens up a new field of research and potential applications in nanoplasmonics and optoelectronics.

cond-mat.mes-hall↗