Showing papers on "Plasmon published in 1980"
IBM1
TL;DR: In this paper, the influence of a dense plasma of hot electrons and holes on the primary channels of energy relaxation and redistribution of photoexcited carriers in Si, particularly collisions between carriers, plasmon emission, impact ionization, phonon emission, and carrier diffusion, has been determined.
Abstract: Calculations have been made to determine the influence of a dense plasma of hot electrons and holes on the primary channels of energy relaxation and redistribution of photoexcited carriers in Si, particularly collisions between carriers, plasmon emission, impact ionization, phonon emission, and carrier diffusion. At high carrier densities, Auger recombination is sufficiently fast to ensure that the electrons and holes rapidly reach quasiequilibrium with a common quasi-Fermi level at a temperature which is lowered by the partitioning of energy into thermally excited plasmons. The appropriate dielectric function has been calculated. At sufficiently high temperatures and carrier densities, energy can diffuse at a rate that is comparable to (and, in some cases, faster than) the rate at which the energy is transferred to the lattice. The steady-state carrier density and temperature, and consequently the ultimate extent to which the lattice is heated, depend critically on the parameters of the exciting laser.
228 citations
TL;DR: In this paper, a nonradiative energy transfer from excited dye molecules near a metal surface to plasmon surface polaritons has been investigated experimentally using the Langmuir-Blodgett technique, and the coupling efficiency measured with the inverse attenuated-total-reflection technique.
162 citations
TL;DR: In this article, a local-orbital formulation of the Dyson equation is presented for the one-particle Green's function with the self-energy expressed in terms of a dynamically screened interaction which includes local-field and excitonic effects.
Abstract: A local-orbital formulation of the Dyson equation is presented for the one-particle Green's function with the self-energy expressed in terms of a dynamically screened interaction which includes local-field and excitonic effects. Also presented is a quantitative calculation of the quasiparticle states for diamond from first principles, which demonstrates the different roles played by two-particle excitations (electron-hole, plasmon). A discussion of the implications for local-density and empirical one-electron concepts is given.
132 citations
TL;DR: The theoretical literature on plasmons in inversion layers is briefly reviewed in this article, and the results to date generally show a remarkable agreement with simple theory, although interesting deviations are seen at low densities.
103 citations
TL;DR: In this paper, anomalous low-frequency Raman scattering from localized acoustic vibrations of roughness features on a metal surface is observed, arising from resonant laser excitation of localized dipolar plasmons.
Abstract: Anomalous, low-frequency Raman scattering from localized acoustic vibrations of roughness features on a metal surface are observed. The observed mode frequency shifts with excitation frequency and with the index of refraction of the surrounding medium. The shifts arise from resonant laser excitation of localized dipolar plasmons. This resonant optical coupling is a key to the phenomenon of enhanced Raman scattering from molecules adsorbed on rough metal surfaces.
102 citations
TL;DR: In this paper, the authors measured the variation in the Raman intensity of a thin polystyrene coated onto a metal holographic grating as a function of the angle of incidence of the exciting laser beam.
Abstract: The variation in the Raman intensity of a thin film of polystyrene coated onto a Ag metal holographic grating has been measured as a function of the angle of incidence of the exciting laser beam. The Raman signal reaches its maximum intensity at the angle at which the laser excites the plasmon surface polariton mode of the metal directly by coupling through the grating vector. This demonstrates that plasmon surface polariton fields can be exploited to enhance the Raman spectra of very thin films on metal surfaces. The advantages of using holographic gratings in this type of experiment are briefly discussed.
91 citations
TL;DR: In this paper, a collimated beam of white light is dispersed by a prism, and then focused by a cylindrical lens onto the base of a second prism coated with a thin metal film.
Abstract: Simple optical techniques are described for the direct visual observation of the plasmon surface polariton dispersion curve, ω vs κ, and of the shift in the dispersion curve from overcoatings of different thicknesses. To see the dispersion curve, a collimated beam of white light is dispersed by a prism, and then focused by a cylindrical lens onto the base of a second prism coated with a thin metal film. With this arrangement the attenuated total reflection spectrum is obtained with all the visible frequencies spatially resolved. The shift of the dispersion curve for coatings of different thicknesses is illustrated in a separate experiment using a specially constructed Langmuir wedge. This demonstrates the usefulness of plasmon surface polaritons for monitoring coatings with thicknesses of the order of nanometers.
76 citations
TL;DR: In this paper, a 2-n electron probe size was used to detect bulk plasmon excitations in single 5-50 nm dia.c. spheres with a 2 nm probe size.
69 citations
TL;DR: In this paper, an infinite summation method is used to obtain the intrinsic photoemission spectrum of a conduction electron in the sudden limit, and it is predicted that an electron at the bottom of the conduction band should have an asymmetry index comparable to that of a core electron.
Abstract: An infinite summation method is used to obtain the intrinsic photoemission spectrum of a conduction electron in the sudden limit. It is predicted that an electron at the bottom of the conduction band should have an asymmetry index comparable to that of a core electron and that the strengths of its plasmon satellites should be similar to those of a core electron. The width of their plasmon satellites, however, should become smaller under the influence of recoil. In essence, our results show that the exchange-correlation hole left after a photoemitted conduction electron has a very similar effect as the core hole left after a photoemitted core electron. Use of synchrotron radiation gives high enough a resolution to make possible the verification of these effects.
67 citations
IBM1
TL;DR: In this paper, surface enhanced Raman scattering from molecular monolayers adsorbed on a holographic grating and covered by Ag has been studied, and the angular dependence of surface Raman cross-sections can arise from scattering of surface plasmon polaritons into light by localized molecular vibrations.
65 citations
TL;DR: In this article, surface roughness influences the Raman and fluorescence spectra of adsorbed molecules since it allows excitation of surface evanescent fields which increase the induced dipole moment of the molecule.
TL;DR: In this paper, the experimental realization of trapped silver atoms in various matrix supports, with emphasis placed on optical absorption, emission and e.r.s. spectroscopic properties.
Abstract: This paper starts with the experimental realization of trapped silver atoms in various matrix supports, with emphasis placed on optical absorption, emission and e.s.r. spectroscopic properties. Special attention is devoted to ground- and excited-state silver atom interactions with the surrounding matrix cage of atoms, particularly with respect to the recently discovered phenomenon of light-induced diffusion and aggregation of silver atoms to small, precisely defined silver clusters. Various aspects and applications of photodiffusion methods are highlighted and some pertinent comparisons are made with metal concentration and bulk annealing approaches as alternatives to controlled metal nucleation. This will lead to the embryonic clusters Ag2 and Ag3 for which there now exists considerable spectroscopic, photochemical and theoretical information. Silver-containing bimetallic clusters, generated either by metal concentration deposition or photoaggregation methods, will be a natural extension to the Ag2,3 presentation; their relevance to bimetallic cluster catalysts will be briefly contemplated. The concept of generating anionic silver clusters by Na/Ag photoionization methods will be briefly described, with reference to the parent Ag– anion. In considering the higher silver clusters, one is now in a position to evaluate experimentally the genesis of silver nucleation from the stage of an isolated silver atom, through to a six-atom array and to higher, less well defined aggregates. With these data one can attempt to track the evolving optical and e.s.r. properties by reference to the build-up of cluster electronic states calculated by way of SCF-Xα-SW molecular-orbital procedures for assumed cluster geometries. The observation of rudimentary interband transitions of silver clusters in the range 6-13 atoms, that absorb in a similar energy region to the collective electronic excitations associated with plasmon absorption of silver microcrystallites, simultaneously with the evolution of conduction electron spin resonance absorption, whose observed linewidths and g-shifts conform to the theoretical predictions of Kubo and Kawabata, can in principle provide a valuable criterion on which to judge the atomic composition at which optical–electronic characteristics of silver aggregates transform from those of the molecular to the bulk state. Future directions in diatomic-metal and metal-cluster chemistry are briefly contemplated in the light of recent break-throughs with ambient-temperature metal-vapour–liquid-polymer techniques and the discovery of polymer-supported, very low nuclearity metal cluster, generated and stable at, or very close to, room temperature.
IBM1
TL;DR: Several studies of the Raman spectra of organic molecules on metal surfaces are described; included among these are: the enhancement of Raman signals by direct excitation of plasmon surface polaritons on holographic metal gratings and the wavelength dependence of the breathing mode vibrations of pyridine adsorbed on an anodized Ag electrode as discussed by the authors.
TL;DR: In this article, a review of the recombination mechanisms for narrow-gap semiconductors is presented, including the Auger effect and the magnetic quantum effect, as well as some fundamental properties of the semiconductor.
TL;DR: In this paper, the authors explored the theory of energy transfer between an infrared dipole and a metal surface and found that the normalized rates and energy transfer quantum yields can be extremely large as compared with electronic energy transfer in the visible and ultraviolet.
Abstract: The quantitative results and qualitative understanding of the classical electromagnetic theory of energy transfer between an infrared dipole and a metal surface are explored. There are two limiting regimes: (1) a short range behavior where the rates decrease as D−3, and a long range behavior where rates decrease exponentially with D. For the analyzed surfaces, these regimes essentially represent transfer to bulk excitations and to surface plasmons, respectively. In the D−3 region, the normalized rates and energy transfer quantum yields can be extremely large as compared with electronic energy transfer in the visible and ultraviolet. A 1000 cm−1, perpendicularly oriented dipole 4000 A from a Sn surface has a 69% energy transfer quantum yield. Extrapolation to molecules actually ’’on’’ metal surfaces suggests 10−9–10−11 sec lifetimes. Energy transfer to plasmons is explored for plasmons of varying lifetimes and electric field dependences.
TL;DR: In this article, the effects of self-generated magnetic field in laser produced plasmas on the parametric decay of an extraordinary electromagnetic wave into two upper hybrid plasmons is examined for arbitrary magnetic field intensity and arbitrary ratio k/k0-sub 0.2.
Abstract: The effects of self-generated magnetic field in laser produced plasmas on the parametric decay of an extraordinary electromagnetic wave into two upper hybrid plasmons is examined for arbitrary magnetic field intensity and arbitrary ratio k/k0-sub 0. Due to the presence of magnetic field, the linear Landau damping is greatly reduced and the spectrum of unstable modes is significantly modified for k lambda sub D approximately 0.2.
TL;DR: In this paper, the self-consistency requirement for the plasmon dispersion and damping coefficients was solved for a one component plasma in the k → 0 limit through a simple hydrodynamical "ansatz" for the response function.
TL;DR: In this paper, the physics of surface plasmon polaritons (SPP) were discussed and experiments on the influence of SPP dispersion by the potential changes in the double layer regime, by the crystal structure of the surface, by overlayers and by roughness and the use of attenuated total reflection SPP resonance in Raman scattering from adsorbates.
TL;DR: In this article, the electroreflectance spectra of thin Ag films from the submonolayer range up to about 20 monolayers, electrodeposited onto Cu(111) electrodes have been studied in the photon energy range between 1.6 and 5.3 eV.
TL;DR: In this article, the effect of thermal degradation of InP surface on the low-energy electron loss spectrum is reported. And the bulk-plasmon peak of indium metal appears alongside that of inP. The method is applicable to other III-V compounds and generally to compounds for which a constituent part is a metal capable of segregation.
Abstract: We report the effect of thermal degradation of InP surface on the low‐energy electron‐loss spectrum: the bulk‐plasmon peak of indium metal appears alongside that of InP. We propose the use of this technique to detect metallic microsclusters on; the surface of InP epitaxial layers. An example is given of an epilayer grown by chemical‐vapor deposition. The method is applicable to other III‐V compounds, and generally to compounds for which a constituent part is a metal capable of segregation.
TL;DR: In this paper, the negative differential resistance that has been observed in the currentvoltage characteristics of some metal-insulator-metal (MIM) diodes is investigated theoretically and a refined theory involving the stimulated inelastic tunneling of electrons through the diode's insulating layer is developed to explain the negative resistance.
Abstract: The negative differential resistance that has been observed in the current-voltage characteristics of some metal-insulator-metal (MIM) diodes is investigated theoretically. A refined theory, involving the stimulated inelastic tunneling of electrons through the diode's insulating layer, is developed to explain the negative resistance. Electrons can tunnel inelastically through the insulating layer by emitting surface plasmons. It is shown that if the diode structure forms a resonant cavity of the proper frequency and sufficiently high Q -factor, the effect of emitted plasmons can be contained long enough to stimulate additional inelastic tunneling. Second order perturbation theory is used to derive an equation for the current-voltage characteristic of an MIM diode exhibiting negative differential resistance. Numerical calculations show that a Q -factor of 10^{2}-10^{4} is required to match the theoretical results to published current-voltage characteristics of MIM diodes with negative differential resistance.
TL;DR: In this paper, the effect of the plasmon and acoustic plasmons on superconductivity in two-subband systems in MOS inversion layers by numerical solutions of the gap equation in the weak-coupling theory was investigated.
Abstract: The effect of the plasmon and/or the acoustic plasmon on superconductivity is investigated in two-subband systems in MOS inversion layers by numerical solutions of the gap equation in the weak-coupling theory of superconductivity, in which the effective interactions are evaluated in the RPA. When the carrier concentration of the system is low, it is shown that the p]asmon plays the main role in the superconductivity, while when it is high, the primary contribution comes from the acoustic plasmon. Several criteria to get a high transition temperature are obtained. The Si(100)/SiO 2 system is predicted to show the super-conducting behavior at the temperatures around 1 mK.
TL;DR: In this article, a simple theoretical analysis of the properties of plasmon modes at a bimetallic interface reveals that the observed excitation known as an "interface plasmons" is not a pure mode but arises from excitations of plasms in a narrow band of states.
Abstract: A simple theoretical analysis of the properties of plasmon modes at a bimetallic interface reveals that the observed excitation known as an 'interface plasmon' is not a pure mode but arises from excitations of plasmons in a narrow band of states. The interface is responsible for the presence of this band but the states within the band are not spatially localised in the interface region.
TL;DR: In this article, the secondary electron (SE) spectrum, energy loss (EL) spectrum and Auger electron spectrum (AES) for pure Al were measured by low-energy electron-reflection spectroscopy.
Abstract: The secondary‐electron (SE) spectrum, energy‐loss (EL) spectrum, and Auger electron spectrum (AES) for pure Al were measured by low‐energy electron‐reflection spectroscopy. The SE spectrum taken at primary energies higher than 50 eV is compared to the spectrum at 30 eV when excitation of surface and bulk plasmons is negligible. Both spectra do not change in the peak position and shape. Therefore the contribution of secondary electrons emitted by plasmon decay is negligibly small compared to the contribution of those emitted by the single‐electron excitations. Some additional peaks are observed in EL and SE when O2 is sorbed on the surface.
TL;DR: In this article, the roughness-coupled radiation from surface plasmons was shown to dominate the emission of Ag films irradiated by low energy electrons (20-1500 eV).
TL;DR: In this paper, the effect of the vacuum interface on the electronic structure of metals was explored using X-ray photoelectron spectroscopy (XPS), and a narrowed and shifted surface density of states was isolated and a surface atom core level shift was resolved.
TL;DR: In this paper, the surface phonons, bulk phonons and two-dimensional plasmons couple together to form a three-branched surface plasmaron spectrum.