Negative Refractive Index in Hydrodynamical Systems

We discuss the presence of exotic electromagnetic phenomena in systems with finite charge density which are described by hydrodynamics. We show that such systems generically have negative refractive index for low frequency electromagnetic waves, i.e. the energy flux and the phase velocity of the wave propagate in opposite directions. We comment on possible phenomenological applications, focusing on the Quark Gluon Plasma.Comment: 16 pages, 2 figure

Strongly anisotropic media: the THz perspectives of left-handed materials

We demonstrate that non-magnetic ($\mu \equiv 1$) left-handed materials can be effectively used for waveguide imaging systems. We also propose a specific THz realization of the non-magnetic left-handed material based on homogeneous, naturally-occurring media

Refractive index in holographic superconductors

With the probe limit, we investigate the behavior of the electric permittivity and effective magnetic permeability and related optical properties in the s-wave holographic superconductors. In particular, our result shows that unlike the strong coupled systems which admit a gravity dual of charged black holes in the bulk, the electric permittivity and effective magnetic permeability are unable to conspire to bring about the negative Depine-Lakhtakia index at low frequencies, which implies that the negative phase velocity does not appear in the holographic superconductors under such a situation.Comment: JHEP style, 1+15 pages, 11 figures, version to appear in JHE

Magnetoelastic nonlinear metamaterials

We introduce the concept of magnetoelastic metamaterials with electromagnetic properties depending on elastic deformation. We predict a strong nonlinear and bistable response of such metamaterials caused by their structural reshaping in response to the applied electromagnetic field. In addition, we demonstrate experimentally the feasibility of the predicted effect.Comment: 4 pages, 5 figure

Strong coupling between surface plasmon polaritons and Sulforhodamine 101 dye

We demonstrate a strong coupling between surface plasmon polaritons and Sulforhodamine 101 dye molecules. Dispersion curves for surface plasmon polaritons on samples with a thin layer of silver covered with Sulforhodamine 101 molecules embedded in SU-8 polymer are obtained experimentally by reflectometry measurements and compared to the dispersion of samples without molecules. Clear Rabi splittings, with energies up to 360 and 190 meV, are observed at the positions of the dye absorption maxima. The split energies are dependent on the number of Sulforhodamine 101 molecules involved in the coupling process. Transfer matrix and coupled oscillator methods are used to model the studied multilayer structures with a great agreement with the experiments. Detection of the scattered radiation after the propagation provides another way to obtain the dispersion relation of the surface plasmon polaritons and, thus, provides insight into dynamics of the surface plasmon polariton/dye interaction, beyond the refrectometry measurements

Strong light-matter coupling in two-dimensional atomic crystals

Two dimensional (2D) atomic crystals of graphene, and transition metal dichalcogenides have emerged as a class of materials that show strong light-matter interaction. This interaction can be further controlled by embedding such materials into optical microcavities. When the interaction is engineered to be stronger than the dissipation of light and matter entities, one approaches the strong coupling regime resulting in the formation of half-light half-matter bosonic quasiparticles called microcavity polaritons. Here we report the evidence of strong light-matter coupling and formation of microcavity polaritons in a two dimensional atomic crystal of molybdenum disulphide (MoS2) embedded inside a dielectric microcavity at room temperature. A Rabi splitting of 46 meV and highly directional emission is observed from the MoS2 microcavity owing to the coupling between the 2D excitons and the cavity photons. Realizing strong coupling effects at room temperature in a disorder free potential landscape is central to the development of practical polaritonic circuits and switches.Comment: 25 pages, 7 figure

Electronic excitations in organic microcavities with strong light-matter coupling

The electronic excitations in non-cavity materials with broad and dispersionless electronic resonances are localized (i.e. incoherent, the wave vector being not a 'good' quantum number). This picture changes drastically in structures with strong resonant light-matter interaction. We present here a short review of theoretical and experimental results and as example we discuss the excitations in a planar microcavity, which utilizes organic materials as the optically resonant semiconductor. As it follows from macroscopic theory, as a result of strong light-matter coupling two polariton branches appear which are analogous to the cavity-polariton branches observed in inorganic microcavities. However, the polariton branches only exist in a certain restricted intervals of wave vectors. The majority of the electronic excited states do not strongly couple to the cavity photon, and these states are localized. We compare these predictions with results of numerical simulation of a disordered one-dimensional microcavity in the strong coupling regime. In this numerical simulations, the translational symmetry breaking due to disorder scattering is explicitly taken into account. The results qualitatively demonstrate the same structure of spectrum as obtained in the macroscopic theory for planar microcavity. They also give the possibility to analyse in the one-dimensional case the character of the wave functions both in real space and in Fourier space determining the intervals of wave vectors, where coherent (polaritonic) states exist and estimating for different spectral regions the radius of localized (incoherent) states. (C) 2001 Elsevier Ltd. All rights reserved