13 research outputs found
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
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
On the use of graphene for quad-band THz microstrip antenna array with diversity reception for biomedical applications
Analysis of photonic band gaps in metamaterial-based one-dimensional ternary photonic crystals
Negative Refraction and Superconductivity
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. © SISSA 2011.SCOPUS: ar.jinfo:eu-repo/semantics/publishe