Search results for "SURFACE PLASMON"
showing 10 items of 393 documents
Influence of an Electron Beam Exposure on the Surface Plasmon Resonance of Gold Nanoparticles
2013
Electron beam imaging is a common technique used for characterizing the morphology of plasmonic nanostructures. During the imaging process, the electron beam interacts with traces of organic material in the chamber and produces a well-know layer of amorphous carbon over the specimen under investigation. In this paper, we investigate the effect of this carbon adsorbate on the spectral position of the surface plasmon in individual gold nanoparticles as a function of electron exposure dose. We find an optimum dose for which the plasmonic response of the nanoparticle is not affected by the imaging process. The final publication is available at link.springer.com
Dynamical Casimir-Polder interaction between an atom and surface plasmons
2013
We investigate the time-dependent Casimir-Polder potential of a polarizable two-level atom placed near a surface of arbitrary material, after a sudden change in the parameters of the system. Different initial conditions are taken into account. For an initially bare ground-state atom, the time-dependent Casimir-Polder energy reveals how the atom is "being dressed" by virtual, matter-assisted photons. We also study the transient behavior of the Casimir-Polder interaction between the atom and the surface starting from a partially dressed state, after an externally induced change in the atomic level structure or transition dipoles. The Heisenberg equations are solved through an iterative techni…
Coupled plasmonic graphene wires: theoretical study including complex frequencies and field distributions of bright and dark surface plasmons
2020
Theoretical research on localized surface plasmons (LSPs) supported by a structure formed by two parallel dielectric wires with a circular cross section wrapped with a graphene sheet has an impact in the practical realm. Here, LSPs are represented in the form of an infinite series of cylindrical multipole partial waves linked to each of the graphene wires. To obtain the kinematics (complex eigenfrequencies) and dynamic characteristics (field distributions) of the LSPs, we consider the analytic extension to the complex plane of the solution to the boundary value problem. The lower frequency LSP group is formed by four branches, two of them corresponding to bright modes and the others to dark…
Stability of soliplasmon excitations at metal/dielectric interfaces
2011
We show the stability features of different families of soliplasmon excitations by analyzing their different propagation patterns under random perturbations of the initial profile. The role of phase and dispersive waves is also unveiled.
Mie plasmon in polyhedral metal clusters
1995
We study the dependence of the classical plasmon frequency on the symmetry of the metal cluster and show that all clusters with at least two three-fold axes have the same plasmon frequency as the spherical cluster, ωp/√3. In these cases the effect of the geometry will only appear in the spill-out correction and in other quantum mechanical corrections.
Optimization of multilayered nanotubes for maximal scattering cancellation
2016
An optimization for multilayered nanotubes that minimizes the scattering efficiency for a given polarization is derived. The cylindrical nanocavities have a radially periodic distribution, and the marginal layers that play a crucial role particularly in the presence of nonlocalities are disposed to reduce the scattering efficiency up to two orders of magnitude in comparison with previous proposals. The predominant causes leading to such invisibility effect are critically discussed. A transfer-matrix formalism is additionally developed for the fast estimation of the scattering efficiency of the nanostructures.
Fluorescence relaxation in the near-field of a mesoscopic metallic particle : distance dependence and role of plasmon modes
2008
International audience; We analytically and numerically analyze the fluorescence decay rate of a quantum emitter placed in the vicinity of a spherical metallic particle of mesoscopic size (i.e with dimensions comparable to the emission wavelength). We discuss the efficiency of the radiative decay rate and non–radiative coupling to the particle as well as their distance dependence. The electromagnetic coupling mechanisms between the emitter and the particle are investigated by analyzing the role of the plasmon modes and their nature (dipole, multipole or interface mode). We demonstrate that near-field coupling can be expressed in a simple form verifying the optical theorem for each particle …
Plasmonic communications : light on a wire
2013
The emerging field of plasmonics promises the generation, processing, transmission, sensing and detection of signals at optical frequencies along metallic surfaces much smaller than the wavelengths they carry. Plasmonic technology has applications in a wide range of fields, including biophotonics, sensing, chemistry and medicine. But perhaps the area where it will have the most profound impact is in optical communications, since plasmonic waves oscillate at optical frequencies and thus can carry information at optical bandwidths.
Plasmon-driven nondiffracting surface beaming
2011
We introduce diffraction-free plasmonic waves in metal-dielectric surfaces which are the analogue to nondiffracting Bessel beams in free space. By interfering multiple converging plane waves with controlled phase matching, we generate a subwavelength transverse spot located at the boundaries of a 1D plasmonic lattice. The diffraction-free beam is resonantly transmitted through the stratiform medium leading not only to light confinement but also to wave enhancement assisted by surface plasmons polaritons. To conclude, we briefly analyze other types of localized surface modes which were proposed recently.
Dipole surface plasmon in large K N + clusters
1993
The dipole surface plasmon forK N + clusters is analyzed using the RPA sum-rule technique within a semiclassical Density Functional Theory and the spherical jellium model. The theoretical frequencies are blue shifted as compared to the experimental ones. The discrepancies between theory and experiment are reduced when considering non-local energy contributions in the density functional and phenomenologically including atomic lattice effects by means of an electron effective mass and a static dielectric constant.