Results

**1 - 4**of**4**### b Physique Théorique et Mathématique and International Solvay Institutes

, 2013

"... We discuss the presence of exotic electromagnetic phenomena in systems with finite charge density which are described by hydrodynamics. We show that such sys-tems generically have negative refractive index for low frequencies electromagnetic waves, i.e. the energy flux and the phase velocity of the ..."

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We discuss the presence of exotic electromagnetic phenomena in systems with finite charge density which are described by hydrodynamics. We show that such sys-tems generically have negative refractive index for low frequencies 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.

### Negative Refraction and Superconductivity

, 2013

"... We discuss exotic properties of charged hydrodynamical systems, in the broken superconducting phase, probed by electromagnetic waves. Motivated by general arguments from hydrodynamics, we observe that negative refraction, namely the propagation in opposite directions of the phase velocities and of t ..."

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We discuss exotic properties of charged hydrodynamical systems, in the broken superconducting phase, probed by electromagnetic waves. Motivated by general arguments from hydrodynamics, we observe that negative refraction, namely the propagation in opposite directions of the phase velocities and of the energy flux, is expected for low enough frequencies. We corroborate this general idea by analyzing a holographic superconductor in the AdS/CFT correspondence, where the response functions can be explicitly computed. We study the dual gravitational theory both in the probe and in the backreacted case. We find that, while in the first case the refractive index is positive at every frequency, in the second case there is negative refraction at low enough frequencies. This is in agreement with hydrodynamic considerations.

### Helmholtz equation. REFERENCES

"... factory performance for computing the scattering amplitudes; (ii) the equations for shape parameters decouple and the numerical procedure for the inversion problem becomes very efficient, thus resulting in a very satisfactory shape recovery for exact data. Due to the ill-posed nature of the inverse ..."

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factory performance for computing the scattering amplitudes; (ii) the equations for shape parameters decouple and the numerical procedure for the inversion problem becomes very efficient, thus resulting in a very satisfactory shape recovery for exact data. Due to the ill-posed nature of the inverse problems, shape recovery and its resolution were found to be sensitive to the data noise. How-ever, shape recovery of the part of the scatterer facing the line source was found to be more satisfactory. Thus, changing the location of the line source can be used in a stabilization procedure to reduce the effect of noise on the inversion result. ACKNOWLEDGMENTS

### Investigation of the Propagation Characteristics of Magnetostatic Surface Waves in a Layered Structure of Left-Handed Materials

"... The characteristics of magnetostatic surface waves at microwave frequencies in a layered structure of left-handed material film and a semi-infinite linear ferrite substrate have been investigated. The general dispersion relation is derived and analyzed numerically. It is found that it has two soluti ..."

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The characteristics of magnetostatic surface waves at microwave frequencies in a layered structure of left-handed material film and a semi-infinite linear ferrite substrate have been investigated. The general dispersion relation is derived and analyzed numerically. It is found that it has two solutions for ω(k), one represents a physical solution and other unacceptable. The effects of the applied external magnetic field around the proposed region have also been examined.