Transformation-Optics Description of Nonlocal Effects in Plasmonic Nanostructures

We develop an insightful transformation-optics approach to investigate the impact that nonlocality has on the optical properties of plasmonic nanostructures. The light-harvesting performance of a dimer of touching nanowires is studied by using the hydrodynamical Drude model, which reveals nonlocal resonances not predicted by previous local calculations. Our method clarifies the interplay between radiative and nonlocal effects in this nanoparticle configuration, which enables us to elucidate the optimum size that maximizes its absorption and field enhancement capabilitiesThis work was supported by the ESF plasmonbionanosense program, the Leverhulme Trust, and the Engineering and Physical Sciences Research Council (EPSRC

Understanding Bowtie Nanoantennas Excited by a Localized Emitter

A full analytical description of a bowtie nanoantenna excited by a localized emitter is presented using the transformation electromagnetic technique. By applying the conformal mapping, the bowtie nanoantenna is transformed into a periodic multi-parallel plate transmission line problem which can be easily evaluated analytically providing physical insight of the coupling between the dipole nanoemitter and the bowtie nanoantenna. The non-radiative Purcell enhancement spectrum is evaluated both analytically and numerically for different lengths, arm angles and metals, demonstrating a good agreement between both approaches. The method here presented fills the gap of the design techniques for optical nanoantennas

Homogeneous metamaterial description of localised spoof plasmonics in spiral geometries

It has been recently shown that ultrathin spiral metamaterials can support localized spoof plasmon modes whose resonant wavelength is much larger than the size of the structure. Here, an analytical model is developed to describe the electromagnetic properties of the two-dimensional version of these devices: a perfect conducting wire corrugated by spiral grooves. The emergence of localized spoof plasmons in this geometry is quantitatively investigated. Calculations show that these modes can be engineered through the spiral angle and the number of grooves. The theory also allows us to elucidate the contribution of magnetic and electric localized spoof plasmons to the optical response of these metamaterial devices. Finally, experimental evidence of the existence of these modes in extremely thin textured copper disks is also presented

Engineering the Phase Front of Light with Phase-Change Material Based Planar lenses

International audienc

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Search for neutral MSSM Higgs bosons decaying to a pair of tau leptons in pp collisions

Peer reviewe

Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV

Peer reviewe

Measurement of top quark–antiquark pair production in association with a W or Z boson in pp collisions at √s=8 TeV

Peer reviewe