A 2d Honeycomb Photonic Crystal Under Applied Magnetic Fields

The band-structure properties of a photonic two-dimensional honeycomb lattice formed by cylindrical semiconductor shell rods with dielectric permitivities ε 1 and ε 2, and embedded in a background with permitivity ε 3, is studied by using an standard plane-wave expansion. The properties of bandgaps and density of states, considering dispersive dielectric responses, are investigated together with the possibility of fabricating systems with tunable photonic bandgaps, due to the Voigt magneto-optical effect, under the influence of an external magnetic field. © 2008 SPIE.7138J. D. Joannopoulos, R. D. Meade, J. N. Winn, Photonic Crystals: Molding the Flow of Light, Princeton University Press, Princeton, 1995E. Istrate and E. H. Sargent, Rev. Mod. Phys. 78, 455 (2006)Xu, C., Hu, X., Li, Y., Liu, X., Fu, R., Zi, J., (2003) Phys. Rev. B, 68, p. 193201Kee, C.-S., Kim, J.-E., Park, H.Y., Park, I., Lim, H., (2000) Phys. Rev. B, 61, p. 15523Anderson, C.M., Giapis, K.P., (1996) Phys. Rev. Lett, 77, p. 2949Rezaei, B., Kalafi, M., (2006) Optics Commun, 266, p. 159Busch, K., John, S., (1999) Phys. Rev. Lett, 83, p. 967S. B. Cavalcanti, M. de Dios-Leyva, E. Reyes-Gómez, and L. E. Oliveira, Phys. Rev. B 74, 153102 (2006)ibid., Phys. Rev. E 75, 026607 (2007)Ho, K.M., Chan, C.T., Soukoulis, C.M., (1990) Phys. Rev. Lett, 65, p. 315

A Taste Of Photonics: Band Structure, Null Gaps, Non-bragg Gaps, And Symmetry Properties Of One-dimensional Superlattices

We have investigated the propagation of plane waves through one-dimensional superlattices composed of alternate layers characterized by two different refractive indexes, which may take on positive as well as negative values. For both indices of refraction positive we have found null-gap points for commensurate values of the optical path lengths of each layer at which the superlattice becomes transparent. We have determined the symmetry properties of the electromagnetic field demonstrating the degeneracy of the solutions at these points. Furthermore, we have been able to characterize non-Bragg gaps that show up in frequency regions in which the average refractive index is null, by obtaining analytically the non-Bragg gap width which depends only on the ratio b/a of the layer widths.6726Rayleigh, L., (1887) Phil. Mag, 24 (256), p. 5. , SVeselago, V.G., (1968) Sov. Phys. Usp, 10, p. 509Parimi, P.V., Lu, W.T., Vodo, P., Sridhar, S., (2003) Nature, 426, p. 404Cubuku, E., Aydin, K., Ozbay, E., Foteinopolou, S., Soukoulis, C.M., (2003) Phys. Rev. Lett, 91, p. 207401Yeh, P., Yariv, A., Hong, C.-S., (1977) J. Opt. Soc. Am, 67, p. 423Cavalcanti, S.B., de Dios-Leyva, M., Reyes-Gómez, E., Oliveira, L.E., (2006) Phys. Rev. B, 74, p. 153102(2007) Phys. Rev. E, 75, p. 026607Eleftheriades, G.V., Yyer, A.K., Kremer, P.C., (2002) IEEE Trans. Microwave Theory Tech, 50, p. 2702Li, J., Zhou, L., Chan, C.T., Sheng, P., (2003) Phys. Rev. Lett, 90, p. 08390

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02