The Experts below are selected from a list of 37773 Experts worldwide ranked by ideXlab platform
Fabian Pauly - One of the best experts on this subject based on the ideXlab platform.
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plasmon polaritons in cubic lattices of spherical Metallic Nanoparticles
Physical Review B, 2018Co-Authors: Simon Lamowski, Charlieray Mann, Felicitas Hellbach, Eros Mariani, Guillaume Weick, Fabian PaulyAbstract:We theoretically investigate plasmon polaritons in cubic lattices of spherical Metallic Nanoparticles. The Nanoparticles, each supporting triply-degenerate localized surface plasmons, couple through the Coulomb dipole-dipole interaction, giving rise to collective plasmons that extend over the whole metamaterial. The latter hybridize with photons forming plasmon polaritons, which are the hybrid light-matter eigenmodes of the system. We derive general analytical expressions to evaluate both plasmon and plasmon-polariton dispersions and the corresponding eigenstates. These are obtained within a Hamiltonian formalism, which takes into account retardation effects in the dipolar interaction between the Nanoparticles and considers the dielectric properties of the Nanoparticles as well as their surrounding. Within this model we predict polaritonic splittings in the near-infrared to the visible range of the electromagnetic spectrum that depend on polarization, lattice symmetry, and wave-vector direction. Finally, we show that the predictions of our model are in excellent quantitative agreement with conventional finite-difference frequency-domain simulations, but with the advantages of analytical insight and significantly reduced computational cost.
Mingpu Wang - One of the best experts on this subject based on the ideXlab platform.
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size and shape dependent melting temperature of Metallic Nanoparticles
Materials Chemistry and Physics, 2004Co-Authors: Mingpu WangAbstract:A new model accounting for the particle size and shape dependent melting temperature of Metallic Nanoparticles is proposed in this paper, where the particle shape is considered by introducing a shape factor. It is shown that the particle shape can affect the melting temperature of Nanoparticles, and the particle shape effect on the melting temperature become larger with decreasing of the particle size. The present calculation results on the melting temperature of Sn, Pb, In and Bi Nanoparticles are well consistent with the corresponding experimental values and better than these given by liquid drop model.
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the particle size dependence of cohesive energy of Metallic Nanoparticles
Chemical Physics Letters, 2003Co-Authors: Weihong Qi, Mingpu Wang, G Y XuAbstract:Based on the concept that the cohesive energy can be regarded as the required energy to separate the Metallic crystal into individual atoms by destroying the Metallic bonds, a method is developed in this letter to calculate the cohesive energy of Metallic Nanoparticles. The calculation predictions are consistent with the experimental values of Mo and W Nanoparticles.
Simon Lamowski - One of the best experts on this subject based on the ideXlab platform.
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plasmon polaritons in cubic lattices of spherical Metallic Nanoparticles
Physical Review B, 2018Co-Authors: Simon Lamowski, Charlieray Mann, Felicitas Hellbach, Eros Mariani, Guillaume Weick, Fabian PaulyAbstract:We theoretically investigate plasmon polaritons in cubic lattices of spherical Metallic Nanoparticles. The Nanoparticles, each supporting triply-degenerate localized surface plasmons, couple through the Coulomb dipole-dipole interaction, giving rise to collective plasmons that extend over the whole metamaterial. The latter hybridize with photons forming plasmon polaritons, which are the hybrid light-matter eigenmodes of the system. We derive general analytical expressions to evaluate both plasmon and plasmon-polariton dispersions and the corresponding eigenstates. These are obtained within a Hamiltonian formalism, which takes into account retardation effects in the dipolar interaction between the Nanoparticles and considers the dielectric properties of the Nanoparticles as well as their surrounding. Within this model we predict polaritonic splittings in the near-infrared to the visible range of the electromagnetic spectrum that depend on polarization, lattice symmetry, and wave-vector direction. Finally, we show that the predictions of our model are in excellent quantitative agreement with conventional finite-difference frequency-domain simulations, but with the advantages of analytical insight and significantly reduced computational cost.
Joachim R Krenn - One of the best experts on this subject based on the ideXlab platform.
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surface plasmon resonances of single and coupled Metallic Nanoparticles a boundary integral method approach
Physical Review B, 2005Co-Authors: Ulrich Hohenester, Joachim R KrennAbstract:We employ the boundary integral method for the calculation of plasmon resonances in single and coupled Metallic Nanoparticles. A generic and versatile scheme is developed that allows us to compute the optical properties of arbitrarily shaped Nanoparticles embedded in dielectric environments with complex geometry. In the static limit an eigenvalue problem is formulated whose solutions directly provide the plasmon resonances. We present results for spherical, cylindrical, and cubic particles, and discuss the role of coupling and retardation.
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spectroscopy of single Metallic Nanoparticles using total internal reflection microscopy
Applied Physics Letters, 2000Co-Authors: Carsten Sonnichsen, Joachim R Krenn, F R Aussenegg, S Geier, N E Hecker, G Von Plessen, Jochen Feldmann, Harald Ditlbacher, Bernhard Lamprecht, Vanessa Zh ChanAbstract:We have developed a simple, fast, and flexible technique to measure optical scattering spectra of individual Metallic Nanoparticles. The particles are placed in an evanescent field produced by total internal reflection of light from a halogen lamp in a glass prism. The light scattered by individual particles is collected using a conventional microscope and is spectrally analyzed by a nitrogen-cooled charge-coupled-device array coupled to a spectrometer. This technique is employed to measure the effect of particle diameter on the dephasing time of the particle plasmon resonance in gold Nanoparticles. We also demonstrate the use of this technique for measurements in liquids, which is important for the potential application of particle plasmons in chemical or biological nanosensors.
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squeezing the optical near field zone by plasmon coupling of Metallic Nanoparticles
Physical Review Letters, 1999Co-Authors: Joachim R Krenn, Alain Dereux, Jeanclaude Weeber, E Bourillot, Y Lacroute, J P Goudonnet, Gerburg Schider, W Gotschy, A Leitner, F R AusseneggAbstract:The study of electromagnetic eigenmodes of small metal particles is motivated by fundamental research and by possible applications of the optical properties of such particles. Most experimental works involve a large number of small metal particles embedded inside a dielectric material or deposited on a surface. The particles were studied as disordered or ordered arrays [1,2]. In both cases, their optical properties were affected by statistical and /or collective effects. The shape and size inhomogeneities of a large array of small metal particles lead to a statistical averaging of the optical properties. Collective effects due to the multiple scattering of light between the particles become significant when the distance between the particles is reduced to the order of magnitude of the incident wavelength. A recent experiment [3] determined the homogeneous linewidth of the plasmon resonance of Metallic Nanoparticles. In order to circumvent the inherent broadening associated to the large number of particles, a scanning near-field optical microscope (SNOM) was operated as a subwavelength local antenna to excite single Nanoparticles in the near-field zone. The detection of the transmitted
Eros Mariani - One of the best experts on this subject based on the ideXlab platform.
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plasmon polaritons in cubic lattices of spherical Metallic Nanoparticles
Physical Review B, 2018Co-Authors: Simon Lamowski, Charlieray Mann, Felicitas Hellbach, Eros Mariani, Guillaume Weick, Fabian PaulyAbstract:We theoretically investigate plasmon polaritons in cubic lattices of spherical Metallic Nanoparticles. The Nanoparticles, each supporting triply-degenerate localized surface plasmons, couple through the Coulomb dipole-dipole interaction, giving rise to collective plasmons that extend over the whole metamaterial. The latter hybridize with photons forming plasmon polaritons, which are the hybrid light-matter eigenmodes of the system. We derive general analytical expressions to evaluate both plasmon and plasmon-polariton dispersions and the corresponding eigenstates. These are obtained within a Hamiltonian formalism, which takes into account retardation effects in the dipolar interaction between the Nanoparticles and considers the dielectric properties of the Nanoparticles as well as their surrounding. Within this model we predict polaritonic splittings in the near-infrared to the visible range of the electromagnetic spectrum that depend on polarization, lattice symmetry, and wave-vector direction. Finally, we show that the predictions of our model are in excellent quantitative agreement with conventional finite-difference frequency-domain simulations, but with the advantages of analytical insight and significantly reduced computational cost.
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dirac like plasmons in honeycomb lattices of Metallic Nanoparticles
Physical Review Letters, 2013Co-Authors: Guillaume Weick, Claire Woollacott, W L Barnes, Ortwin Hess, Eros MarianiAbstract:We consider a two-dimensional honeycomb lattice of Metallic Nanoparticles, each supporting a localized surface plasmon, and study the quantum properties of the collective plasmons resulting from the near-field dipolar interaction between the Nanoparticles. We analytically investigate the dispersion, the effective Hamiltonian, and the eigenstates of the collective plasmons for an arbitrary orientation of the individual dipole moments. When the polarization points close to the normal to the plane, the spectrum presents Dirac cones, similar to those present in the electronic band structure of graphene. We derive the effective Dirac Hamiltonian for the collective plasmons and show that the corresponding spinor eigenstates represent Dirac-like massless bosonic excitations that present similar effects to electrons in graphene, such as a nontrivial Berry phase and the absence of backscattering off smooth inhomogeneities. We further discuss how one can manipulate the Dirac points in the Brillouin zone and open a gap in the collective plasmon dispersion by modifying the polarization of the localized surface plasmons, paving the way for a fully tunable plasmonic analogue of graphene.