arXiv subjects

Daria A. Smirnova

Publications and source records attributed to Daria A. Smirnova.

31 records · Page 2Linked to original sources

arXiv2018

Nonlinear generation of quantum-entangled photons from high-Q states in dielectric nanoparticles

We develop multipolar theory of nonlinear generation of entangled photons from subwavelength dielectric particles due to the spontaneous parametric downconversion. We demonstrate that optical excitation in resonance with the high-quality supercavity mode of the aluminum gallium arsenide (AlGaAs) nanodisk leads to a strong enhancement of generation of entangled photon pairs associated with electric and magnetic dipole modes. Our rigorous numerical results are corroborated by an analytical model, universally describing formation of high-$Q$ resonant states and dark states due to the interference and interplay of the parent multipoles, namely, magnetic dipoles and magnetic octupole. Our findings and description can be instructive for quantum and nonlinear nanophotonics applications.

physics.optics↗

arXiv2018

Ring Dirac Solitons in Nonlinear Topological Lattices

We study solitons of the two-dimensional nonlinear Dirac equation with asymmetric cubic nonlinearity. We show that, with the nonlinearity parameters specifically tuned, a high degree of localization of both spinor components is enabled on a ring of certain radius. Such ring Dirac soliton can be viewed as a self-induced nonlinear domain wall and can be implemented in nonlinear photonic graphene lattice with Kerr-like nonlinearities. Our model could be instructive for understanding localization mechanisms in nonlinear topological systems.

physics.optics↗

arXiv2017

Spin and valley polarized one-way Klein tunneling in photonic topological insulators

Advances of condensed matter physics in exploiting the spin degree of freedom of electrons led to the emergence of the field of spintronics, which envisions new and more efficient approaches to data transfer, computing, and storage [1-3]. These ideas have been inspiring analogous approaches in photonics, where the manipulation of an artificially engineered pseudo-spin degrees of freedom is enabled by synthetic gauge fields acting on light [4,5,6]. The ability to control these additional degrees of freedom can significantly expand the landscape of available optical responses, which may revolutionize optical computing and the basic means of controlling light in photonic devices across the entire electromagnetic spectrum. Here we demonstrate a new class of photonic systems, described by effective Hamiltonians in which competing synthetic gauge fields engineered in pseudo-spin, chirality/sublattice and valley subspaces result in band gap opening at one of the valleys, while the other valley exhibits Dirac-like conical dispersion. It is shown that such effective response has dramatic implications on photon transport, among which: (i) spin-polarized and valley-polarized one-way Klein tunneling and (ii) topological edge states that coexist within the Dirac continuum for opposite valley and spin polarizations. These phenomena offer new ways to control light in photonics, in particular for on-chip optical isolation, filtering and wave-division multiplexing by selective action on their pseudo-spin and valley degrees of freedom.

cond-mat.mtrl-sci↗

arXiv2017

Controlling scattering of light through topological transitions in all-dielectric metasurfaces

Topological phase transitions in condensed matter systems have shown extremely rich physics, unveiling such exotic states of matter as topological insulators, superconductors and superfluids. Photonic topological systems open a whole new realm of research exhibiting a number of important distinctions from their condensed matter counterparts. Photonic modes can couple to the continuum of free space modes which makes it feasible to control and manipulate scattering properties of the photonic structure via topology. At the same time, the direct connection of scattering and topological properties of the photonic states allows their probing by spectroscopic means via Fano resonances. Here we demonstrate that the radiative coupling of modes supported by an all-dielectric metasurface can be controlled and tuned under topological phase transitions due to band inversion, correspondingly inducing a distinct switching of the quality factors of the resonances associated with the bands. In addition, we develop a technique to retrieve the topological properties of all-dielectric metasurfaces from the measured far-field scattering characteristics. The collected angle-resolved transmission and reflection spectra allow extracting the momentum-dependent frequencies and lifetimes of the photonic modes. This enables retrieval of the effective photonic Hamiltonian, including the effects of a synthetic gauge field, and topological invariants~-- pseudo-spin Chern numbers. Our results thus open a new avenue to design a new class of metasurfaces with unique scattering characteristics controlled via topological effects. This work also demonstrates how topological states of open systems can be explored via far-field measurements.

cond-mat.mtrl-sci↗

arXiv2016

Multipolar third-harmonic generation driven by optically-induced magnetic resonances

We analyze third-harmonic generation from high-index dielectric nanoparticles and discuss the basic features and multipolar nature of the parametrically generated electromagnetic fields near the Mie-type optical resonances. By combining both analytical and numerical methods, we study the nonlinear scattering from simple nanoparticle geometries such as spheres and disks in the vicinity of the magnetic dipole resonance. We reveal the approaches for manipulating and directing the resonantly enhanced nonlinear emission with subwavelength all-dielectric structures that can be of a particular interest for novel designs of nonlinear optical antennas and engineering the magnetic optical nonlinear response at nanoscale.

physics.optics↗

arXiv2015

Tunable nonlinear graphene metasurfaces

We introduce the concept of nonlinear graphene metasurfaces employing the controllable interaction between a graphene layer and a planar metamaterial. Such hybrid metasurfaces support two types of subradiant resonant modes, asymmetric modes of structured metamaterial elements ("metamolecules") and graphene plasmons exhibiting strong mutual coupling and avoided dispersion crossing. High tunability of graphene plasmons facilitates strong interaction between the subradiant modes, modifying the spectral position and lifetime of the associated Fano resonances. We demonstrate that strong resonant interaction, combined with the subwavelength localization of plasmons, leads to the enhanced nonlinear response and high efficiency of the second-harmonic generation.

physics.optics↗

arXiv2015

Observation of topological edge modes in bianisotropic metamaterials

Existence of robust edge modes at interfaces of topologically dissimilar systems is one of the most fascinating manifestations of a novel nontrivial state of matter, topological insulators. Such electronic states were originally predicted and discovered in condensed matter physics, but they find their counterparts in other fields of physics, including the physics of classical waves and electromagnetics. Here, we present the first experimental realization of a topological insulator for electromagnetic waves based on engineered bianisotropic metamaterials. By employing the near-field scanning technique, we demonstrate experimentally the topologically robust propagation of electromagnetic waves around sharp corners without back reflection.

cond-mat.mes-hall↗

arXiv2015

Cascaded third harmonic generation in hybrid graphene-semiconductor waveguides

We study cascaded harmonic generation of hybrid surface plasmons in integrated planar waveguides composed of a graphene layer and a doped-semiconductor slab. We derive a comprehensive model of cascaded third harmonic generation through phase-matched nonlinear interaction of fundamental, second harmonic and third harmonic plasmonic modes supported by the structure. We show that hybrid graphene-semiconductor waveguides can simultaneously phase-match these three interacting harmonics, increasing the total third-harmonic output by a factor of 5 compared to the non-cascaded regime.

physics.optics↗

arXiv2015

Discrete solitons in graphene metamaterials

We study nonlinear properties of multilayer metamaterials created by graphene sheets separated by dielectric layers. We demonstrate that such structures can support localized nonlinear modes described by the discrete nonlinear Schrödinger equation and that its solutions are associated with stable discrete plasmon solitons. We also analyze the nonlinear surface modes in truncated graphene metamaterials being a nonlinear analog of surface Tamm states.

cond-mat.mes-hall↗

arXiv2014

Dissipative plasmon solitons in graphene nanodisk arrays

We study nonlinear modes in one-dimensional arrays of doped graphene nanodisks with Kerr-type nonlinear response in the presence of an external electric field. We present the theoretical model describing the evolution of the disks' polarizations, taking into account intrinsic graphene losses and dipole-dipole coupling between the graphene nanodisks. We reveal that this nonlinear system can support discrete dissipative scalar solitons of both longitudinal and transverse polarizations, as well as vector solitons composed of two mutually coupled polarization components. We demonstrate the formation of stable resting and moving localized modes under controlling guidance of the external driving field.

physics.optics↗

arXiv2014

Dynamics and stability of dark solitons in exciton-polariton condensates

We present a comprehensive analytical theory of localized nonlinear excitations - dark solitons, supported by an incoherently pumped, spatially homogeneous exciton-polariton condensate. We show that, in contrast to dark solitons in conservative systems, these nonlinear excitations "relax" by blending with the background at a finite time, which critically depends on the parameters of the condensate. Our analytical results for trajectory and lifetime are in excellent agreement with direct numerical simulations of the open-dissipative mean-field model. In addition, we show that transverse instability of quasi-one-dimensional dark stripes in a two-dimensional open-dissipative condensate demonstrates features that are entirely absent in conservative systems, as creation of vortex-antivortex pairs competes with the soliton relaxation process.

cond-mat.quant-gas↗

arXiv2013

Dissipative plasmon-solitons in multilayer graphene

Nonlinear properties of a multi-layer stack of graphene sheets are studied. It is predicted that such a structure may support dissipative plasmon-solitons generated and supported by an external laser radiation. Novel nonlinear equations describing spatial dynamics of the nonlinear plasmons driven by a plane wave in the Otto configuration are derived and the existence of single and multi-hump dissipative solitons in the graphene structure is predicted.

physics.optics↗

arXiv2013

Extraordinary localization of TE-waves at the graphene layer

The propagation of electromagnetic waves along the surface of a nonlinear dielectric covered by a graphene layer is investigated. The main result is that such a surface can support and stabilize nonlinear transverse electric (TE) plasmon polaritons. We demonstrated that these nonlinear TE modes have a subwavelength localization in the direction perpendicular to the surface, with the intensity much higher than that of the incident wave which excites the polariton.

cond-mat.mes-hall↗