arXiv subjects

Viktoriia E. Babicheva

Publications and source records attributed to Viktoriia E. Babicheva.

At least 19 recordsLinked to original sources

arXiv2026

Graduate Training in Quantum Information Science and Engineering: Lessons, Challenges, and a Roadmap from the NSF Research Traineeship Programs

Since 2019, eighteen NSF Research Traineeship (NRT) awards in quantum information science and engineering (QISE) and adjacent fields have been funded, constituting the largest NSF-coordinated investment in graduate QISE training in the United States. Synthesizing lessons from our programs, we work through the central tensions that every QISE graduate program must negotiate: between depth in a home discipline and breadth across the field, between structured instruction and open-ended experiential and hands-on learning, and between training individual specialists and cultivating teams that collectively cover all areas of QISE. We describe the structural and pedagogical innovations the NRT programs have developed in response, assess what is working and what remains unresolved, and sketch 12 open problems the community will need to address as QISE graduate education scales beyond the well-resourced research universities where it has up till now been mainly concentrated. Eight concrete recommendations follow: (1) adopt the startup model of team-based training as an organizing philosophy; (2) invest immediately in sensing and communication curriculum development; (3) build student agency into program governance, not just activities; (4) establish structural mechanisms for industrial engagement rather than depending on goodwill; (5) design for sustainability from year one; (6) develop graduate-level textbooks spanning all three QISE pillars: computing, sensing, and communications; (7) establish shared outcome assessment instruments across programs; and (8) develop structured mechanisms for faculty professional development in QISE.

physics.ed-ph↗

arXiv2018

Lattice effect on electric and magnetic resonance overlap in periodic array

Designing the shape of silicon nanoparticles has been shown to be an effective approach to increasing overlap between electric and magnetic dipole resonances thereby achieving directional scattering and decrease of reflection. Variations of disk diameter and/or height affect resonances differently and can thus result in resonance overlap. In most of the studies, the disks are arranged in a periodic array where the periodicity is varied together with disk diameter, but the role of lattice effect is neglected. Here we theoretically study a periodic array of disks and show that the contribution of the lattice effect in shifting resonance positions is comparable to the effect of the diameter change. We demonstrate that the lattice effect is important even when the wavelength of diffraction remains on the blue side from electric and magnetic dipole resonances and there are no additional lattice resonances are excited. Period and disk dimensions are chosen so that the resonances overlap in the proximity of the telecommunication wavelength which is of great practical interest.

physics.optics↗

arXiv2018

Lattice resonances under oblique light incidence on nanoparticle array

Ultra-thin optical structures, known as metasurfaces, have shown promising light controlling capability at the nanoscale. In this paper, we study their particular case, a periodic array of high-refractive-index nanoparticles with electric and magnetic resonances. The main result of the work is a numerical demonstration that the lattice effect in the periodic arrangement of nanoparticles changes the resonance position even if the resonances are above the diffraction wavelength (Rayleigh anomaly). We show that the disk resonance changes can be achieved not only by varying periods of the array under normal light incidence but also by changing the incident angle.

physics.optics↗

arXiv2018

Resonant transmission suppression in high-index nanoparticle arrays

High-index nanoparticle lattices have attracted a lot of interest recently as they support both optical electric and magnetic resonances and can serve as functional metasurfaces. Here we demonstrate that under particular conditions, the all-dielectric nanoparticle metasurfaces can resonantly suppress transmission. Electric and magnetic dipole resonances of silicon nanoparticle arrays are studied in the air and in the dielectric matrix in visible and near-infrared spectral ranges. We show that the wave resonantly scattered forward by the one or both electric and magnetic dipole moments of nanoparticles can destructively interfere with the incident wave, providing significant suppression of the transmission through the array. The reported effect can find important applications in different fields related to optics and photonics such as the development of filters, sensors, and solar cells.

physics.optics↗

arXiv2018

Nanoparticle lattices with electric and magnetic resonances [Prospective]

Lattice resonances in nanoparticle arrays recently have gained a lot of attention because of the possibility to produce spectrally narrow resonant features in transmission and reflection as well as significantly increase absorption in the structures. Most of the efforts so far have been put to study these lattice resonances in dipole approximation. However, the recent research shows that higher multipoles not only produce resonant feature but are also involved in cross-coupling, affect each other, and induce a magnetoelectric response. In this Prospective, we review the recent achievements in studying of interplay and coupling of different multipoles in periodic nanoparticle arrays and share our vision on further progress of the field.

physics.optics↗

arXiv2018

Near-field Surface Waves in Few-Layer MoS2

Recently emerged layered transition metal dichalcogenides have attracted great interest due to their intriguing fundamental physical properties and potential applications in optoelectronics. Using scattering-type scanning near-field optical microscope (s-SNOM) and theoretical modeling, we study propagating surface waves in the visible spectral range that are excited at sharp edges of layered transition metal dichalcogenides (TMDC) such as molybdenum disulfide and tungsten diselenide. These surface waves form fringes in s-SNOM measurements. By measuring how the fringes change when the sample is rotated with respect to the incident beam, we obtain evidence that exfoliated MoS2 on a silicon substrate supports two types of Zenneck surface waves that are predicted to exist in materials with large real and imaginary parts of the permittivity. We have compared MoS2 interference fringes with those formed on layered insulator such as hexagonal boron nitride where only leaky modes are possible due to its small permittivity. Interpretation of experimental data is supported by theoretical models. Our results could pave the way to the investigation of surface waves on TMDCs and other van der Waals materials and their novel photonics applications.

cond-mat.mes-hall↗

arXiv2018

Electric quadrupole and magnetic dipole coupling in plasmonic nanoparticle arrays

Collective resonances in plasmonic nanoparticle arrays with electric dipole moment oriented along the lattice wave propagation are theoretically investigated. The role of electric quadrupole (EQ) and magnetic dipole (MD) moments of gold nanoparticles in the resonant features of the arrays is analyzed. We perform both semi-analytical calculations of coupled multipole equations and rigorous numerical simulations varying contributions of the electric and magnetic multipoles by changing particle size and shape (spheres and disks). The arrays in homogeneous and non-homogeneous environments are considered. We find that even very weak non-resonant EQ and MD moments of a single particle are significantly enhanced in the periodic lattice at the wavelength of collective (lattice) resonance excitation. Importantly, we show that in the infinite arrays, the EQ and MD moments of nanoparticles are coupled and affect each other resonant contributions. We also demonstrate that at the lattice-resonance wavelength, the enhanced EQ and MD moments have contributions to reflection comparable to the dipole one resulting in a significant decrease of reflection and providing the satisfaction of the generalized Kerker condition for reflection suppression.

physics.optics↗

arXiv2018

Reflection suppression by the hyperbolic-medium antennas and silicon particles

Optical antennas made out of materials with hyperbolic dispersion is an alternative approach to realizing efficient subwavelength scatterers and may overcome limitations imposed by plasmonic and all-dielectric designs. Recently emerged natural hyperbolic material hexagonal boron nitride supports phonon-polariton excitations with low optical losses and high anisotropy. Here we study scattering properties of the hyperbolic-medium (HM) antennas, and in particular, we consider a combination of two types of the particles - HM bars and silicon spheres - arranged in a periodic array. We analyze excitation of electric and magnetic resonances in the particles and effect of their overlap in the array. We theoretically demonstrate that decrease of reflectance from the array can be achieved with appropriate particle dimensions where electric and magnetic resonances of different particle types overlap, and the resonance oscillations are in phase. In this case, generalized Kerker condition is satisfied, and particle dimers in the array efficiently scatter light in the forward direction. The effect can be used in designing metasurfaces based on hexagonal boron nitride scatterers with an application in mid-infrared photonics.

physics.optics↗

arXiv2017

Surface and edge resonances of phonon-polaritons in scattering-type near-field optical microscopy

We theoretically study resonance responses of flat surfaces and sharp edges of the nanostructures that support excitations of phonon-polaritons in mid-infrared range. We focus on two materials: silicon carbide that has a nearly isotropic permittivity and hexagonal boron nitride that has a strong anisotropy and spectral band with hyperbolic dispersion. We aim to predict scattering-type near-field optical microscope (s-SNOM) response and develop a modeling approach that adequately describes the resonant behavior of the nanostructure with phonon-polaritons. The previously employed technique assumes dipole scattering from the tip and allows calculating s-SNOM signal in different demodulation orders by modeling full structure, any tip positions, and vertical scans, which works well for the structures with only one hot spot, e.g. flat surfaces. In the structures of complex shapes, hot-spot places are unknown, and analysis of light absorption in the whole apex is the best way to account for all hot spots and field enhancement. We show that calculation of demodulation orders of light absorption in the tip is an alternative way to predict s-SNOM signal, and it is preferred for the structures of complex shapes with strong resonances, where dipole approximation of the tip is not valid.

physics.optics↗

arXiv2017

Near-field edge fringes at sharp material boundaries

We have studied the formation of near-field fringes when sharp edges of materials are imaged using scattering-type scanning near-field optical microscope (s-SNOM). Materials we have investigated include dielectrics, metals, near-perfect conductor, and those that possess anisotropic permittivity and hyperbolic dispersion. For our theoretical analysis, we use a technique that combines full-wave numerical simulations of tip-sample near-field interaction and signal demodulation at higher orders akin to what is done in typical s-SNOM experiments. Unlike previous tip-sample interaction near-field models, our advanced technique allows simulation of the realistic tip and sample structure. Our analysis clarifies edge imaging of recently emerged layered materials such as hexagonal boron nitride and transition metal dichalcogenides (in particular, molybdenum disulfide), as well as traditional plasmonic materials such as gold. Hexagonal boron nitride is studied at several wavelengths, including the wavelength where it possesses excitation of phonon-polaritons and hyperbolic dispersion. Based on our results of s-SNOM imaging in different demodulation orders, we specify resonant and non-resonant types of edges and describe the edge fringes for each case. We clarify near-field edge-fringe formation at material sharp boundaries, both outside bright fringes and the low-contrast region at the edge, and elaborate on the necessity of separating them from propagating waves on the surface of polaritonic materials.

physics.optics↗

arXiv2017

Hyperbolic-metamaterial waveguides for long-range propagation

We study optical waveguides that include layers of materials and metamaterials with hyperbolic dispersion (HMM). We consider long-range regime at the dielectric-HMM interface in different waveguide geometries (single interface or symmetric cladding with different layers). In contrast to the traditional analysis of geometrical parameters, we make emphasis on optical properties of constituent materials, and by solving dispersion equations, analyze how dielectric and HMM permittivities affect propagation length and mode size. We derive a figure of merits that should be used for each waveguide in a broad range of permittivity values as well as compare them with plasmonic waveguides. We show conventional plasmonic quality factor, which is the ratio of real to imaginary parts of permittivity, is not applicable to the case of waveguides with complex structure. Both telecommunication wavelengths and mid-infrared spectral ranges are of interest considering recent advances in van der Waals materials such as hexagonal boron nitride. Finally, we evaluate the performance of the waveguides with hexagonal boron nitride in the range where it possesses hyperbolic dispersion (6.2-7.3 um), and we identify the optimum wavelength for each type of the waveguide.

physics.optics↗

arXiv2017

Multipole resonances and directional scattering by hyperbolic-media antennas

We propose to use optical antennas made out of natural hyperbolic material hexagonal boron nitride (hBN), and we demonstrate that this medium is a promising alternative to plasmonic and all-dielectric materials for realizing efficient subwavelength scatterers and metasurfaces based on them. We theoretically show that particles out of hyperbolic medium possess different resonances enabled by the support of high-k waves and their reflection from the particle boundaries. Among those resonances, there are electric quadrupole excitations, which cause magnetic resonance of the particle similar to what occurs in high-refractive-index particles. Excitations of the particle resonances are accompanied by the drop in the reflection from nanoparticle array to near-zero value, which can be ascribed to resonant Kerker effect. If particles are arranged in the spacer array with period d, narrow lattice resonances are possible at wavelength d, d/2, d/3 etc. This provides an additional degree of control and possibility to excite resonances at the wavelength defined by the array spacing. For the hBN particle with hyperbolic dispersion, we show that the full range of the resonances, including magnetic resonance and a decrease of reflection, is possible.

physics.optics↗

arXiv2017

Resonant lattice Kerker effect in metasurfaces with electric and magnetic optical responses

To achieve efficient light control at subwavelength dimensions, plasmonic and all-dielectric nanoparticles have been utilized both as a single element as well as in the arrays. Here we study 2D periodic nanoparticle arrays (metasurfaces) that support lattice resonances near the Rayleigh anomaly due to the electric dipole (ED) and magnetic dipole (MD) resonant coupling between the nanoparticles. Silicon and core-shell particles are considered. We demonstrate for the first time that, choosing of lattice periods independently in each mutual-perpendicular direction, it is possible to achieve a full overlap between the ED-lattice resonance and MD resonances of nanoparticles in certain spectral range and to realize the resonant lattice Kerker effect (resonant suppression of the scattering or reflection). At the effect conditions, the strong suppression of light reflectance in the structure is appeared due to destructive interference between electromagnetic waves scattered by ED and MD moments of every nanoparticle in the backward direction with respect to the incident light wave. Influence of the array size on the revealed reflectance and transmittance behavior is discussed. The resonant lattice Kerker effect based on the overlap of both ED and MD lattice resonances is also demonstrated.

physics.optics↗

arXiv2014

Transition absorption as a mechanism of surface photoelectron emission from metals

Transition absorption of electromagnetic field energy by an electron passing through a boundary between two media with different dielectric permittivities is considered both classically and quantum mechanically. It is shown that transition absorption can make a substantial contribution to the process of electron photoemission from metals due to the surface photoelectric effect.

cond-mat.mes-hall↗

arXiv2014

Plasmonic waveguides with hyperbolic multilayer cladding

Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any homogenization, we calculate the resonant eigenmodes of the finite-width cladding layers, and find agreement with the resonant features in the dispersion of the cladded waveguides. We show that at the resonant widths, the propagating modes of the waveguides are coupled to the cladding eigenmodes and hence, are strongly absorbed. By avoiding the resonant widths in the design of the actual waveguides, the strong absorption can be eliminated.

physics.optics↗

arXiv2014

Plasmonic waveguides cladded by hyperbolic metamaterials

Strongly anisotropic media with hyperbolic dispersion can be used for claddings of plasmonic waveguides. In order to analyze the fundamental properties of such waveguides, we analytically study 1D waveguides arranged of a hyperbolic metamaterial (HMM) in a HMM-Insulator-HMM (HIH) structure. We show that hyperbolic metamaterial claddings give flexibility in designing the properties of HIH waveguides. Our comparative study on 1D plasmonic waveguides reveals that HIH-type waveguides can have a higher performance than MIM or IMI waveguides.

physics.optics↗

arXiv2014

Bismuth ferrite as low-loss switchable material for plasmonic waveguide modulator

We propose new designs of plasmonic modulators, which can be utilized for dynamic signal switching in photonic integrated circuits. We study performance of plasmonic waveguide modulator with bismuth ferrite as an active material. The bismuth ferrite core is sandwiched between metal plates (metal-insulator-metal configuration), which also serve as electrodes so that the core changes its refractive index under applied voltage by means of partial in-plane to out-of-plane reorientation of ferroelectric domains in bismuth ferrite. This domain switch results in changing of propagation constant and absorption coefficient, and thus either phase or amplitude control can be implemented. Efficient modulation performance is achieved because of high field confinement between the metal layers, as well as the existence of mode cut-offs for particular values of the core thickness, making it possible to control the signal with superior modulation depth. For the phase control scheme, π phase shift is provided by 0.8-μm length device having propagation losses 0.29 dB/μm. For the amplitude control, we predict up to 38 dB/μm extinction ratio with 1.2 dB/μm propagation loss. In contrast to previously proposed active materials, bismuth ferrite has nearly zero material losses, so bismuth ferrite based modulators do not bring about additional decay of the propagating signal.

physics.optics↗

arXiv2014

Photonic band-gap engineering for volume plasmon polaritons in multiscale multilayer hyperbolic metamaterials

We theoretically study the propagation of large-wavevector waves (volume plasmon polaritons) in multilayer hyperbolic metamaterials with two levels of structuring. We show that when the parameters of a subwavelength metal-dielectric multilayer ("substructure") are modulated ("superstructured") on a larger, wavelength scale, the propagation of volume plasmon polaritons in the resulting multiscale hyperbolic metamaterials is subject to photonic band gap phenomena. A great degree of control over such plasmons can be exerted by varying the superstructure geometry. When this geometry is periodic, stop bands due to Bragg reflection form within the volume plasmonic band. When a cavity layer is introduced in an otherwise periodic superstructure, resonance peaks of the Fabry-Perot nature are present within the stop bands. More complicated superstructure geometries are also considered. For example, fractal Cantor-like multiscale metamaterials are found to exhibit characteristic self-similar spectral signatures in the volume plasmonic band. Multiscale hyperbolic metamaterials are shown to be a promising platform for large-wavevector bulk plasmonic waves, whether they are considered for use as a new kind of information carrier or for far-field subwavelength imaging.

physics.optics↗