arXiv subjects

Ivan Shelykh

Publications and source records attributed to Ivan Shelykh.

12 recordsLinked to original sources

arXiv2026

Strong coupling regimes of an organic exciton mirror in a microcavity

The coherent, periodic energy transfer between light- and matter excitations characterizes the strong coupling regime of cavity exciton-polaritons, resulting, in the simplest case, in a Rabi-doublet in the spectral domain. We demonstrate a peculiar regime of strong light-matter coupling, which arises when photonic cavity modes couple to an ultra-thin excitonic mirror. We embed a 12 nm J-aggregated thin film in an open microcavity and tune the coupling strength from weak to the onset of ultrastrong coupling. At resonance, the excitonic mirror selectively changes dielectric to metallic field boundary conditions adding a 2{\pi} phase, which links optical cavity modes of different order. Our work gives an exciting perspective to ultra-fast cavity switches and photonic devices based on excitonic optical elements.

cond-mat.mes-hall↗

arXiv2022

Bulk ReSe2: record high refractive index and biaxially anisotropic material for all-dielectric nanophotonics

We show that bulk rhenium diselenide, ReSe2 is characterized by record high value of the refractive index exceeding 5 in near-infrared frequency range. We use back focal plane reflection spectroscopy to extract the components of the ReSe2 permittivity tensor and reveal its extreme biaxial anisotropy. We also demonstrate the good agreement between the experimental data and the predictions of the density functional theory. The combination of the large refractive index and giant optical anisotropy makes ReSe2 a perspective material for all-dielectric nanophotonics in the near-infrared frequency range.

cond-mat.mes-hall↗

arXiv2021

Quantum spin compass models in 2D electronic topological metasurfaces

We consider a metasurface consisting of a square lattice of cylindrical antidots in a two-dimensional topological insulator (2DTI). Each antidot supports a degenerate Kramer's pair of eigenstates formed by the helical topological edge states. We show that the on-site Coulomb repulsion leads to the onset of the Mott insulator phase in the system in a certain range of experimentally relevant parameters. Intrinsic strong spin-orbit coupling characteristic for the 2DTI supports a rich class of the emerging low-energy spin Hamiltonians which can be emulated in the considered system, which makes it an appealing solid state platform for quantum simulations of strongly correlated electron systems.

cond-mat.mes-hall↗

arXiv2020

Ultrafast-nonlinear ultraviolet pulse modulation in an AlInGaN polariton waveguide operating up to room temperature

Ultrafast nonlinear photonics enables a host of applications in advanced on-chip spectroscopy and information processing. These rely on a strong intensity dependent (nonlinear) refractive index capable of modulating optical pulses on sub-picosecond timescales and on length scales suitable for integrated photonics. Currently there is no platform that can provide this for the UV spectral range where broadband spectra generated by nonlinear modulation can pave the way to new on-chip ultrafast (bio-) chemical spectroscopy devices. We demonstrate the giant nonlinearity of UV hybrid light-matter states (exciton-polaritons) up to room temperature in an AlInGaN waveguide. We experimentally measure ultrafast nonlinear spectral broadening of UV pulses in a compact 100 $\mu$m long device and deduce a nonlinearity 1000 times that in common UV nonlinear materials and comparable to non-UV polariton devices. Our demonstration promises to underpin a new generation of integrated UV nonlinear light sources for advanced spectroscopy and measurement.

physics.optics↗

arXiv2020

High refractive index and extreme biaxial optical anisotropy of rhenium diselenide for applications in all-dielectric nanophotonics

We establish simple quantitative criterium for the search of new dielectric materials with high values of the refractive index in the visible range. It is demonstrated, that for light frequencies below the band gap the latter is determined by the dimensionless parameter $\eta$ calculated as the ratio of the sum of the widths of conduction and valence bands and the band gap. Small values of this parameter, which can be achieved in materials with almost flat bands, lead to dramatic increase of the refractive index. We illustrate this rule with a particular example of rhenium dichalcogenides, for which we perform ab-initio calculations of the band structure and optical susceptibility and predict the values of the refractive index > 5 in a wide frequency range around 1 eV together with compratively low losses. Our findings open new perspectives in the search for the new high-index/low loss materials for all-dielectric nanophotonics.

cond-mat.mes-hall↗

arXiv2019

On the origin of blueshifts in organic polariton condensates

We report on the origin of energy-shifts in organic polariton condensates. The localised nature of Frenkel excitons in molecular semiconductors precludes interparticle Coulomb exchange interactions -the latter being the dominant mechanism for blueshifts in inorganic semiconductor microcavities that bear Wannier-Mott excitons. We examine the contribution of optically induced change of the intracavity non-linear refractive index, gain induced frequency-pulling and quenching of the Rabi splitting, as well as the role of polariton-exciton and polariton-polariton scattering in the energy-shift of the polariton mode at condensation threshold in strongly coupled molecular dye microcavities. We conclude that blueshifts in organic polariton condensates arise from the interplay of the saturation of molecular optical transitions and intermolecular energy migration. Our model predicts the commonly observed step-wise increase of both the emission energy and degree of linear polarisation at polariton condensation threshold.

cond-mat.mes-hall↗

arXiv2018

Resonant edge-site pumping of polaritonic Su-Schrieffer-Heeger lattices

We have theoretically investigated Su-Schrieffer-Heeger chains modelled as optical lattices (OL) loaded with exciton-polaritons. The chains have been subject to the resonant pumping of the edge site and shaken in either adiabatic or high-frequency regime. The topological state has been controlled by the relative phases of the lasers constructing the OL. The dynamic problem of the occupation of the lattice sites and eigenstates has been semi-classically solved. Finally, the analysis of the occupation numbers evolution has revealed that gapless, topologically trivial and non-trivial chain configurations demonstrate perceptible behaviour from both qualitative (occupation pattern) and quantitative (total occupation) points of view.

cond-mat.mes-hall↗

arXiv2017

Topological edge state engineering with high-frequency electromagnetic radiation

We outline here how strong light-matter interaction can be used to induce quantum phase transition between normal and topological phases in two-dimensional topological insulators. We consider the case of a HgTe quantum well, in which band inversion occurs above a critical value of the well thickness, and demonstrate that coupling between electron states and the $E$ field from an off-resonant linearly polarized laser provides a powerful tool to control topological transitions, even for a thickness of the quantum well that is below the critical value. We also show that topological phase properties of the edge states, including their group velocity, can be tuned in a controllable way by changing the intensity of the laser field. These findings open up the possibility for new experimental means with which to investigate topological insulators and shed new light on topological-insulator-based technologies that are under active discussion.

cond-mat.mes-hall↗

arXiv2016

Microcavity with saturable nonlinearity under simultaneous resonant and nonresonant pumping: multistability, Hopf bifurcations and chaotic behaviour

We studied optical response of microcavity non-equilibrium exciton-polariton Bose-Einstein condensate with saturable nonlinearity under simultaneous resonant and non-resonant pumping. We demonstrated the emergence of multistabile behavior due to the satutration of the excitonic absorbtion. Stable periodic Rabi- type oscillations of the excitonic and photonic condensate components in the regime of the stationary pump and their transition to the chaotic dynamics through the cascade of Hopf bifurcations by tuning of the electrical pump are revealed.

physics.optics↗

arXiv2010

Reply to "Comment on 'Topological stability of the half-vortices in spinor exciton-polariton condensates'"

In a recent work [H. Flayac, I.A. Shelykh, D.D. Solnyshkov and G. Malpuech, Phys. Rev. B 81, 045318 (2010)], we have analyzed the effect of the TE-TM splitting on the stability of the exciton-polariton vortex states. We considered classical vortex solutions having cylindrical symmetry and we found that the so-called half-vortex states [Yu. G. Rubo, Phys. Rev. Lett. 99, 106401 (2007)] are not solutions of the stationary Gross-Pitaevskii equation. In their Comment [M. Toledo Solano, Yu.G. Rubo, Phys. Rev. B 82, 127301 (2010)], M. Toledo Solano and Yuri G. Rubo claim that this conclusion is misleading and pretend to demonstrate the existence of static half-vortices in an exciton-polariton condensate in the presence of TE-TM splitting. In this reply we explain why this assertion is not demonstrated satisfactorily.

cond-mat.mes-hall↗

arXiv2010

Exciton-polariton mediated superconductivity

We revisit the exciton mechanism of superconductivity in the framework of microcavity physics, replacing virtual excitons as a binding agent of Cooper pairs by excitations of an exciton-polariton Bose-Einstein condensate. We consider a model microcavity where a quantum well with a two dimensional electron gas is sandwiched between two undoped quantum wells, where a polariton condensate is formed. We show that the critical temperature for superconductivity dramatically increases with the condensate population, opening a new route towards high temperature superconductivity.

cond-mat.supr-con↗

arXiv2009

Effect of TE-TM Splitting on the topological stability of half-vortices in exciton-polariton condensates

Half-vortices have been recently shown to be the elementary topological defects supported by a spinor cavity exciton-polaritons condensates with spin anisotropic interactions (Y. G. Rubo, Phys. Rev. Lett. 99, 106401 (2007)). A half vortex is composed by an integer vortex for one circular component of the condensate, whereas the other component remain static. We analyze theoretically the effect of the splitting between TE and TM polarized eigen modes on the structure of the vortices in this system. For TE and TM modes, the polarization states depend on the direction of propagations of particles and imposes some well defined phase relation between the two circular component. As a result elementary topogical defects in this system are no more half vortices but integer vortices correspond to an integer vortex for both circular components of the condensate. The intrinsic life time of half vortices is given and the texture of a few vortex states is analyzed.

cond-mat.mes-hall↗