Search

Your search keyword '"Kivshar, Yuri"' showing total 1,225 results
Start Over Author "Kivshar, Yuri" Publication Type Academic Journals
1,225 results on '"Kivshar, Yuri"'

1. All-dielectric Mie-resonant metaphotonics

Author

Bonod, Nicolas and Kivshar, Yuri

Subjects
All-dielectric nanophotonics, Mie resonances, Kerker effect, Bound states in the continuum, Metaphotonics, Metasurfaces, Physics, QC1-999
Abstract

All-dielectric subwavelength structures made of high-refractive-index materials combine a unique set of advantages in comparison with their plasmonic counterparts. In particular, they can interact resonantly with light through the excitation of both electric and magnetic multipolar Mie-type resonances. This review discusses novel approaches to manipulate light with Mie-resonant dielectric subwavelength structures, spanning from individual nanoparticles to metasurfaces, and covering a broad range of effects, from near-field energy enhancement to far-field beam shaping.

Published
2020
Full Text
View/download PDF

16. Chiral organic molecular structures supported by planar surfaces.

Author

Savin, Alexander V. and Kivshar, Yuri S.

Subjects
*MOLECULAR structure, *MOLECULAR dynamics, *CRYSTAL lattices, *BORON nitride, *HYDROGEN bonding
Abstract

We employ the molecular dynamics simulations to study the dynamics of acetanilide (ACN) molecules placed on a flat surface of planar multilayer hexagonal boron nitride. We demonstrate that the ACN molecules, known to be achiral in the three-dimensional space, become chiral after being placed on the substrate. Homochirality of the ACN molecules leads to stable secondary structures stabilized by hydrogen bonds between peptide groups of the molecules. By employing molecular dynamics simulations, we reveal that the structure of the resulting hydrogen-bond chains depends on the isomeric composition of the molecules. If all molecules are homochiral (i.e., with only one isomer being present), they form secondary structures (chains of hydrogen bonds in the shapes of arcs, circles, and spirals). If the molecules at the substrate form a racemic mixture, then no regular secondary structures appear, and only curvilinear chains of hydrogen bonds of random shapes emerge. A hydrogen-bond chain can form a zigzag array only if it has an alternation of isomers. Such chains can create two-dimensional (2D) regular lattices or 2D crystals. The melting scenarios of such 2D crystals depend on density of its coverage of the substrate. At 25% coverage, melting occurs continuously in the temperature interval 295–365 K. For a complete coverage, melting occurs at 415–470 K due to a shift of 11% of all molecules into the second layer of the substrate. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

17. (INVITED) Roadmap on perovskite nanophotonics

Author

Soci, Cesare, Adamo, Giorgio, Cortecchia, Daniele, Wang, Kaiyang, Xiao, Shumin, Song, Qinghai, Schall-Giesecke, Anna Lena, Cegielski, Piotr J., Lemme, Max C., Gerace, Dario, Sanvitto, Daniele, Tian, Jingyi, Tonkaev, Pavel A., Makarov, Sergey V., Kivshar, Yuri S., Jimenez Gordillo, Oscar A., Melloni, Andrea, Pushkarev, Anatoly P., D'Amato, Marianna, Lhuillier, Emmanuel, and Bramati, Alberto

Published
2023
Full Text
View/download PDF

25. Novel non-plasmonic nanolasers empowered by topology and interference effects

Author

Hwang Min-Soo, Kim Ha-Reem, Jeong Kwang-Yong, Park Hong-Gyu, and Kivshar Yuri

Subjects
bound states in the continuum, mie resonances, nanolaser, spaser, topological photonics, Physics, QC1-999
Abstract

Historically, nanophotonics deals with a control of light at the nanoscale being closely connected with the rapid advances in plasmonics – the physics of surface plasmon polaritons supported by metal–dielectric interfaces. Properly engineered nanostructures allow the subwavelength propagation of light and its strong confinement in nanowaveguides and nanocavities, making possible the field enhancement and lasing. Spaser was suggested as a special type of nanolaser with a very small footprint that can be modulated quickly thus becoming a good candidate for on-chip optical data processing. However, recent developments in the physics of high-index dielectric nanoparticles and resonant dielectric metasurfaces allowed to advance the field of nanophotonics and introduce novel nonplasmonic nanostructures and nanolasers empowered by topology and interference effects. Here we present first some examples of experimentally realized spasers, and then discuss the recent developments in the cutting-edge high-index dielectric nanostructures employed for nonplasmonic nanolasers based on Mie resonances, anapole states, bound states in the continuum, and the physics of topological phases.

Published
2021
Full Text
View/download PDF

26. Third-harmonic generation from Mie-type resonances of isolated all-dielectric nanoparticles.

Author

Melik-Gaykazyan, Elizaveta, Shcherbakov, Maxim, Shorokhov, Alexander, Staude, Isabelle, Brener, Igal, Neshev, Dragomir, Kivshar, Yuri, and Fedyanin, Andrey

Subjects
Mie scattering, nonlinear optics, optical magnetism, silicon nanoparticles, third-harmonic generation
Abstract

Subwavelength silicon nanoparticles are known to support strongly localized Mie-type modes, including those with resonant electric and magnetic dipolar polarizabilities. Here we compare experimentally the efficiency of the third-harmonic generation from isolated silicon nanodiscs for resonant excitation at the two types of dipolar resonances. Using nonlinear spectroscopy, we observe that the magnetic dipolar mode yields more efficient third-harmonic radiation in contrast to the electric dipolar (ED) mode. This is further supported by full-wave numerical simulations, where the volume-integrated local fields and the directly simulated nonlinear response are shown to be negligible at the ED resonance compared with the magnetic one.This article is part of the themed issue New horizons for nanophotonics.

Published
2017

31. Magnetic hyperbolic optical metamaterials.

Author

Kruk, Sergey S, Wong, Zi Jing, Pshenay-Severin, Ekaterina, O'Brien, Kevin, Neshev, Dragomir N, Kivshar, Yuri S, and Zhang, Xiang

Abstract

Strongly anisotropic media where the principal components of electric permittivity or magnetic permeability tensors have opposite signs are termed as hyperbolic media. Such media support propagating electromagnetic waves with extremely large wave vectors exhibiting unique optical properties. However, in all artificial and natural optical materials studied to date, the hyperbolic dispersion originates solely from the electric response. This restricts material functionality to one polarization of light and inhibits free-space impedance matching. Such restrictions can be overcome in media having components of opposite signs for both electric and magnetic tensors. Here we present the experimental demonstration of the magnetic hyperbolic dispersion in three-dimensional metamaterials. We measure metamaterial isofrequency contours and reveal the topological phase transition between the elliptic and hyperbolic dispersion. In the hyperbolic regime, we demonstrate the strong enhancement of thermal emission, which becomes directional, coherent and polarized. Our findings show the possibilities for realizing efficient impedance-matched hyperbolic media for unpolarized light.

Published
2016

38. Stabilization of hydrogen-bonded molecular chains by carbon nanotubes.

Author

Savin, Alexander V. and Kivshar, Yuri S.

Subjects
*CARBON nanotubes, *PROTON conductivity, *HYDROGEN fluoride, *PEPTIDES, *HIGH temperatures
Abstract

We study numerically nonlinear dynamics of several types of molecular systems composed of hydrogen-bonded chains placed inside carbon nanotubes with open edges. We demonstrate that carbon nanotubes provide a stabilization mechanism for quasi-one-dimensional molecular chains via the formation of their secondary structures. In particular, a polypeptide chain (Gly) N placed inside a carbon nanotube can form a stable helical chain (3 10 -, α -, π -, and β -helix) with parallel chains of hydrogen-bonded peptide groups. A chain of hydrogen fluoride molecules ⋯ FH ⋯ FH ⋯ FH can form a hydrogen-bonded zigzag chain. Remarkably, we demonstrate that for molecular complexes (Gly) N ∈ CNT and (FH) N ∈ CNT, the hydrogen-bonded chains will remain stable even at T = 500 K. Thus, our results suggest that the use of carbon nanotubes with encapsulated hydrogen fluoride molecules may be important for the realization of high proton conductivity at high temperatures. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results