Showing papers on "Plasmon published in 1978"
IBM1
TL;DR: In this article, the dispersion of the refractive index of the organic layer was derived by a least square fit of the measured reflectivity curves and it agrees well with other data obtained by different methods.
262 citations
TL;DR: In this paper, the frequency-dependent dipole moment and the radiation emission spectrum for a small particle located above a metal film were calculated and a resonance structure associated with a localized surface plasma mode at a frequency corresponding to the peak in the structure observed in the emission spectra.
Abstract: A resonancelike structure has been reported in the frequency spectrum of light emitted from small-particle tunnel junctions. Here we present a calculation of the frequency-dependent dipole moment and the radiation emission spectrum for a small particle located above a metal film. The dipole moment exhibits a resonance structure associated with a localized surface plasma mode at a frequency corresponding to the peak in the structure observed in the emission spectra.
122 citations
110 citations
TL;DR: The possibility of superconductivity with the aid of the plasmon in two-and three-dimensional single-carrier systems is investigated by numerical solutions of the gap equation in the weak-coupling theory of super-conductivity as discussed by the authors.
Abstract: The possibility of the superconductive state with the aid of the plasmon in two- and three-dimensional single-carrier systems is investigated by numerical solutions of the gap equation in the weak-coupling theory of superconductivity, in which the effective interactions are calculated in the plasmon-pole approximation. The superconductivity does appear in rather low carrier concentrations and the highest attainable transition temperature is of the order of m * /κ 2 degrees Kelvin, where the effective mass, m * , is in the unit of the mass of a free electron and κ is the dielectric constant. Compared with a three-dimensional system, a two-dimensional one is more favorable for the plasmon mechanism of superconductivity, which stems from the difference in the dispersion relation of the plasmon.
110 citations
TL;DR: In this article, the two-dimensional plasmon dispersion relationship in the inversion layer on (100) p -silicon is studied as a function of wave vector q.
57 citations
TL;DR: In this paper, the X-ray photoemission current for an adsorbate core level is calculated for a model which allows the screening of the core hole, both by charge transfer to the adsorbates and by coupling to the surface plasmons.
57 citations
TL;DR: In this paper, the dispersion of plasmons at the surface of a metal and at the interface between two metals is derived by a proper combination of electrodynamics with the hydrodynamic approximation.
Abstract: The dispersion of plasmons at the surface of a metal and at the interface between two metals is derived by a proper combination of electrodynamics with the hydrodynamic approximation. With a two-step model we discuss the effect of a transition region at the surface of a metal and we so explain recent measurements by Krane and Raether for aluminum.
55 citations
TL;DR: In this paper, the authors present experiments that measure the inversion layer conductivity as a function of frequency in the far infrared and propose a prototypic Drude relaxation method for the conductivity measurement.
54 citations
50 citations
TL;DR: In this article, a variational method is presented to calculate dynamic corrections to the image potential of a charged particle at a metal-vacuum interface and hence to calculate its binding energy.
Abstract: A variational method is presented to calculate dynamic corrections to the image potential of a charged particle at a metal-vacuum interface and hence to calculate its binding energy. The response of the metal is treated within the plasmon approximation. As an application, a model for positron surface states on simple metals is studied. It predicts the existence of bound positron surface states in Al, Ga, Zn, Cd, and possibly other high-density simple metals. Further, the resulting localized positron state would have a lifetime 2 to 3 times longer than in the bulk.
49 citations
TL;DR: In this article, the basic equations for surface polaritons originating from phonons, plasmons, excitons and magnons are given, and their observation by ATR is discussed.
Abstract: Recent progress in the field of optical surface modes in semi-infinite crystals is reviewed. The basic equations for surface polaritons originating from phonons, plasmons, excitons and magnons are given. Their observation by ATR, the resulting information and possible applications are discussed.
TL;DR: In this paper, the effects of very thin Ag surface layers on the propagation of surface plasma waves (S.P.W.) excited by ATR at an Al surface are investigated in the vicinity of the Ag plasma frequency and the S.PW dispersion relations, are obtained.
Abstract: 2014 The effects of very thin Ag surface layers on the propagation of surface plasma waves (S.P.W.) excited by ATR at an Al surface are investigated in the vicinity of the Ag plasma frequency and the S.P.W. dispersion relations, are obtained. A splitting of the dispersion curves is found for Ag layers 26, 39 and 58 Å thick, but does not appear for thinner layers. Experimental and computed dispersion curves are compared. LE JOURNAL DE PHYSIQUE TOME 39, JUIN 1978,
TL;DR: Using a pseudopotential with all plane waves up to the second shell in the reciprocal lattice, the dielectric function epsilon (q, omega ) of Al has been calculated as discussed by the authors.
Abstract: Using a pseudopotential with all plane waves up to the second shell in the reciprocal lattice the dielectric function epsilon (q, omega ) of Al has been calculated. For a definite value of the wave vector q the plasma frequency is determined either by the real part of the dielectric function or from the strong peak of the electron-loss function. It is shown that the anisotropy of the plasmon dispersion is fully understood from the electron structure in the one-particle scheme. In addition, the q dependence of the width of the plasmon peak is investigated.
TL;DR: In this article, volume plasmon dispersion and damping of polycrystalline Al and In films have been measured in the wave vector region k
Abstract: Volume plasmon dispersion and damping of polycrystalline Al and In films has been measured in the wave vector region k
TL;DR: In this paper, a surface photoyield spectrum of a metal, namely aluminum, was obtained by fully exploiting the properties of synchrotron radiation, and the extreme surface sensitivity, which is implicit in the transition matrix element for the surface photoexcitation process, was experimentally confirmed.
Abstract: By fully exploiting the properties of synchrotron radiation, a surface photoyield spectrum of a metal, namely aluminum, was obtained for the first time. This type of spectrum has been theoretically discussed since 1928. The extreme surface sensitivity, which is implicit in the transition matrix element for the surface photoexcitation process, was experimentally confirmed. The applied photoemission technique, therefore, provides one of the most powerful tools for the investigation of charge distribution and dielectric response at metal surfaces.
TL;DR: In this paper, the authors present numerical results of a theory for how excited molecules, located above a metal surface, are damped due to excitation of electron-hole pairs and bulk plasmons in the metal.
TL;DR: In this paper, surface plasmons were excited on a silver surface covered with a monolayer of arachidate (26.8 Å) and a monoline of the dye, and the position, halfwidth and the depth of the reflection minimum were strongly dependent on the applied wavelength in the region of the absorption line.
Abstract: The interaction of surface plasmons with a dye monolayer having a rather small absorption band is discussed in this paper. Applying the ATR method surface plasmons were excited on a silver surface covered with a monolayer of arachidate (26.8 Å) and a monolayer of the dye. The position, half-width and the depth of the reflection minimum are strongly dependent on the applied wavelength in the region of the absorption line. The essential features of the measured dependencies can be explained by a simple oscillator model.
TL;DR: The optical absorptivity of ScH2 has been measured at 4.2 K between 0.1 and 4.4 eV, and the dielectric functions determined through Kramers-Kronig analysis as mentioned in this paper.
TL;DR: In this article, it was shown that correlation currents arising from the superposition of pairs of states on distinct sides of a potential barrier in metal-barrier-metal structures can result in inelastic tunneling through the emission of surface plasmons.
Abstract: We show that correlation currents arising from the superposition of pairs of states on distinct sides of a potential barrier in metal‐barrier‐metal structures can result in inelastic tunneling through the emission of surface plasmons. Net gain of an externally excited plasmon field is possible.
TL;DR: In this article, a combined photoemission and electroreflectance investigation was performed on Ag(111 and Ag(100) in contact with an electrolyte, and the optical excitation of surface plasmons was induced on both faces by electrochemically roughening the sample surfaces.
TL;DR: In this paper, surface polaritons in an LO-phonon-plasmon coupled system were studied in cylindrical and semi-infinite geometries.
Abstract: Surface polaritons in an LO-phonon-plasmon coupled system are studied in cylindrical and semi-infinite geometries. Characters of the dispersion relation of the surface polaritons are very different from the case of high carrier electron density and for the case of low density. With electron current the surface polaritons are destabilized in the low-density regime, while they remain stable in the high-density regime.
TL;DR: In this paper, the dependence of the optical properties of the Ge plasma on the electron-phonon coupling constant, the broadening in the plasmon-assisted recombination, and the energy band structure is discussed.
Abstract: Recently, Elci et al. developed a first principles model that accounts for the generation and transient behavior of dense electron-hole plasmas produced in germanium by picosecond optical pulses. The agreement between this model and early experiments is substantial. However, recent transmission measurements, involving optical pulses of varying width, are in disagreement with initial predictions of this model. Here, we emphasize the dependence of the optical properties of the Ge plasma on the electron-phonon coupling constant, the broadening in the plasmon-assisted recombination, and the energy band structure, and we suggest adjustments to the original model that should produce agreement with these more recent experiments. The pulsewidth dependence in the transmission is shown to be sensitive to the relative strengths of the electron-phonon relaxation and the plasmon recombination during the temporal evolution of the hot electron-hole plasma.
TL;DR: In this paper, the real part of the effective dielectric function is derived analytically in the pseudopotential approximation for anyk-direction, and the theory allows the evaluation of the plasmon dispersion,ωp(k), which is found to be anisotropic in general due to band structure effects.
Abstract: The real part of the effective dielectric function is derived analytically in the pseudopotential approximation. For anyk-direction, the theory allows the evaluation of the plasmon dispersion,ωp(k), which is found to be anisotropic in general due to band structure effects. Application of the theory to Al yields an isotropic shift atk=0 ofΔωp(0)v ≈ − 0.3 eV and explains the recently observed anisotropic behaviour of the dispersion very well fork < 0.6kF.
TL;DR: In this paper, a strong resonantlike increase of the electron damping parameter was observed in the region of the coupled LO-phonon-plasmon excitations in $n$-PbTe at low temperatures.
Abstract: A strong resonantlike increase of the electron damping parameter was observed in the region of the coupled LO-phonon-plasmon excitations in $n$-PbTe at low temperatures. This behavior is interpreted as evidence of a generation of collective coupled plasmon-phonon excitations. The experimental results can be interpreted very well by a model calculation as reported recently by Mycielski et al.