arXiv subjects

Zoya Eremenko

Publications and source records attributed to Zoya Eremenko.

3 recordsLinked to original sources

arXiv2026

Resonant Electric-Magnetic Toroidal Duality in Height-Modulated Hexagonal Metasurfaces

Toroidal modes enable high-Q resonances, but electric toroidal excitations remain unexplored compared to magnetic ones. This work establishes electric-magnetic toroidal duality in a hexagonal metasurface. Using finite element simulations, we analyze electric and magnetic toroidal modes in a hexagonal silicon nanorod supercell under mirror-symmetry breaking via height modulation. Eigenfrequencies, Q-factors, power flow, and polarization responses are computed. We identify electric TO and ATO modes with complementary near-field topologies to magnetic analogues. Direct frequency intersections (magnetic and electric TO/ATO) yield high-Q quasi-BICs. Polarization selectivity reverses between families: 0{\deg} excites magnetic TO/electric ATO; 90{\deg} excites magnetic ATO/electric TO. A loss hierarchy (magnetic TO > magnetic ATO > electric ATO > electric TO) and protective layers compatibility are demonstrated. Electric and magnetic toroidal responses are dual manifestations of the same symmetry, providing a unified design framework for high Q metasurfaces in sensing, nonlinear optics, and loss-tolerant devices.

physics.optics↗

arXiv2026

Increasing The Sensitivity of a Surface Plasmon Resonance Sensor using Ti3C2 Mxene

Sensors based on the phenomenon of surface plasmon resonance have limited sensitivity, up to 123 degree/Refractive Index Unit, which restricts their applicability in detecting subtle changes gin biological media (around 10-5 RIU). To address this, a sensor dependent on the Kretschmann-Reather configuration was modified using Ti3C2 MXene material. The sensor was modeled using the finite element method (FEM), yielding the dependence of the wave reflection parameter on the angle of incidence. Founded on these results, the sensitivity of the sensor was calculated and demonstrated a 10% improvement compared to the conventional Kretschmann-Reather configuration. In addition, human biological real-world samples were modeled using refractive index data, and the error of the proposed approach was determined to be approximately 3%.

physics.optics↗

arXiv2025

Enhancing the Propagation Length of Graphene Surface Plasmon Polaritons using a Metamaterial Substrate with a Near-Zero Refractive Index

This paper aims to investigate the conditions necessary to control, enhance, and modify the propagation length of graphene surface plasmon polaritons (SPPs) at room temperature, using an all-dielectric metamaterial substrate in comparison to suspended graphene. The analysis is conducted within a photonic crystal framework using COMSOL Multiphysics 6.2 to study the resonant modes of the all-dielectric metamaterial. Our results confirm the existence of an near-zero effective refractive index (NZERI) regime at the $\Gamma\text{-point}$ point in the photonic crystal approach. At this NZERI regime a consequence of triply degenerate eigenmodes in a certain frequency range occurs when the effective refractive index of the metasurface approaches zero. Our central idea is that the NZERI regime in the all-dielectric metasurface of a graphene substrate can be used to control, enhance, and modify the propagation of SPPs. We applied several independent theoretical methods to obtain the effective refractive index of the metasurface at NZERI frequency range for two-dimensional and three-dimensional metasurface structures with a graphene layer. Simulation results demonstrate that the effective permittivity and permeability simultaneously attain near-zero values at closely spaced yet distinct frequencies, thereby establishing spectral regions with an effectively vanishing refractive index. Key contributions include the first demonstration of NZERI metasurfaces as graphene-supporting platforms for enhancing SPPs, a quantitative approach to balancing propagation distance and field confinement, and practical design guidelines that align with current nanofabrication capabilities. Our simulations further demonstrate that when graphene is placed on (or between two) all-dielectric metasurfaces operating in the NZERI regime, the SPP propagation length can be significantly increased.

physics.optics↗