Surface plasmons on corrugated metal films

The dispersion relation for a surface plasmon, propagating across a corrugated metal film on a dielectric substrate, is obtained by the method of reduced Rayleigh equations. It is found that the surface plasmon dispersion curve has an infinite number of branches. Numerical solutions of the dispersion relation are obtained for a film, characterized by a free-electron metal dielectric function and a sinusoidal profile function.     

Magnetic field effects on slab surface plasmons in the local limit

The local surface plasmon dispersion relation for a slab of plasma in a magnetic field (perpendicular to the slab faces) is analyzed. Magnetic field modifications of both antisymmetric and symmetric slab surface plasmon modes are determined in the local limit.     

The complex dispersion relation of surface plasmon polaritons at gold/para-hexaphenylene interfaces

Two-photon photoemission electron microscopy (2P-PEEM) is used to measure the real and imaginary part of the dispersion relation of surface plasmon polaritons at different interface systems. A comparison of calculated and measured dispersion data for a gold/vacuum interface demonstrates the capability of the presented experimental approach. A systematic 2P-PEEM study on the dispersion relation of dielectric-loaded gold surfaces shows how effective the propagation of surface plasmon polaritons at a gold/para-hexaphenylene interface can be tuned by adjustment of the dielectric film thickness. Deviations of the experimental results from effective index calculations indicate the relevance of thin film peculiarities arising from the details of the growth process and corroborate the need of experimental analysis techniques for dispersion relation measurements.     

Nonlinear dispersion relation for surface plasmon at a metal-Kerr medium interface

The dispersion relation for the plasmon at the interface of a metal and a nonlinear Kerr medium is studied by applying a semi-analytic theory established in the literature. Explicit analytical results are obtained and are compared to those from a certain approximate treatment appeared in the literature. It is found that for large electric field strengths, both the dispersion relation and the surface plasmon frequency from the approximate treatment deviate significantly from those obtained in the exact approach, especially for the case with a negative Kerr susceptibility.     

Theory of the intersurfacedband plasmon

The dispersion relation of the intersurfacedband plasmon, i.e., collective excitation of the surface electrons of the clean or adsorbed surfaces, is investigated by the self-consistent field approach. The dispersion is predicted to start with the linear term in the wave number parallel to the surface, which will be helpful to distinguish the plasmon from the individual excitations. The sign of the dispersion and the depolarization shift depend on the polarization of the interband transition. The contribution of the plasmon to the electron energy loss cross section is given.     

Surface plasmons propagating parallel to the grooves of a large amplitude grating

The dispersion relation is obtained for a surface plasmon propagating parallel to the grooves of a large amplitude grating. Two variants of the Rayleigh method arc used: the first requires the evaluation of the zeros of a determinant; the second yields the dispersion relation in terms of the solution of a matrix eigenvalue problem. The dispersion relations are solved numerically for a sinusoidal and for a symmetric sawtooth grating profile, yielding in each case an infinity of discrete branches.     

Dispersion relation for surface plasmon polaritons in metal/nonlinear-dielectric/metal slot waveguides

We present the first (to our knowledge) exact dispersion relation for the transverse-magnetic surface plasmon polariton (SPP) modes of a plasmonic slot waveguide, which is formed by a nonlinear Kerr medium sandwiched between two metallic slabs. The obtained relation is then simplified to the case of small field intensities, while retaining nonlinear terms, to derive approximate dispersion equations for the symmetric and antisymmetric SPP modes.     

Surface plasmon modes in multi-layer thin-films

The surface plasmon modes in multi-layer thin-film structures of the metal-insulator-metal (MIM) type are modeled using a matrix method for the propagation of electromagnetic waves in stratified media. It is shown that the dispersion relation for the allowed surface plasmon modes is obtained from one of the matrix elements. The fundamental electromagnetic modes are the eigenfunctions of the differential equation for the magnetic field distribution and the eigenvalues are obtained from the dispersion relation. The expansion of an arbitrary wave profile in terms of the eigenfunctions is discussed and applied to the problem of surface plasmons propagating in a structure consisting of seven layers of alternating metal films and dielectrics.     

Plasmon hybridization in metallic nanotubes

We study theoretical formalism of the plasmon hybridization in a metallic nanotube and find an explicit form of the dispersion relation for surface plasmons, in terms of interaction between the bare plasmon modes of the individual surfaces of the nanotubes. In the special case when the longitudinal wave vector is zero (q=0), the plasmon hybridization of a nanotube has a behavior similar to the spherical nanoshell.     

金属和Kerr非线性介质界面上表面等离子体激元的色散关系

从麦克斯韦方程组出发,结合边界条件,分别得到TM波和TE波在金属和Kerr非线性介质界面上表面等离子体激元的色散关系.由于非线性的存在,TM波的色散关系变得复杂,与光强、非线性系数有关.和线性情况一样,此界面不存在TE波.     

Light conduction of metallic two-walled carbon nanotubes

The properties of surface plasmon–polariton modes in metallic two-walled carbon nanotubes are studied, taking into account the retardation effects. The dispersion relation of surface waves is obtained, by solving Maxwell and hydrodynamic equations with appropriate boundary conditions. Numerical results show that the difference between plasmon and plasmon–polariton modes is strongly dependent on the inner-outer radii of the system but only in the long-wavelength cases.     

经典光场相干控制金属纳米线表面等离子体传输

利用全量子力学的方法从理论上研究了利用经典光场相干控制半导体量子点-金属纳米线复合体系中表面等离子体传输特性. 计算中假设金属纳米线表面等离子体具有线性色散关系,半导体量子点具有梯形三能级结构. 分析表明:通过加或不加经典光场,可以控制表面等离子体被反射还是透射;加上光场后,反射峰、透射峰的位置以及两反射峰之间的距离都可以由经典光场控制. 关键词： 表面等离子体 量子点 散射     

Dispersion of cylindrical surface plasmon polaritons in layered structures

The problem of the existence of cylindrical surface plasmon polaritons on thin metal conductors is considered. A dispersion relation is obtained and analyzed, the domain of existence of dispersion curve with a maximum is found, and parametric relations are derived.     

Squeezing visible light waves into a 3-nm-thick and 55-nm-long plasmon cavity

We demonstrate controlled squeezing of visible light waves into nanometer-sized optical cavities. The light is perpendicularly confined in a few-nanometer-thick SiO2 film sandwiched between Au claddings in the form of surface plasmon polaritons and exhibits Fabry-Perot resonances in a longitudinal direction. As the thickness of the dielectric core is reduced, the plasmon wavelength becomes shorter; then a smaller cavity is realized. A dispersion relation down to a surface plasmon wavelength of 51 nm for a red light, which is less than 8% of the free-space wavelength, was experimentally observed. Any obvious breakdowns of the macroscopic electromagnetics based on continuous dielectric media were not disclosed for 3-nm-thick cores.     

Surface plasmon dispersion relation for normal and tangential modes

A theoretical investigation has been made for the surface plasmon dispersion relations for the case of normal and tangential modes to the surface. The hydrodynamical model has been used. We have obtained the dispersion relation by using the continuity of φ and dφ/dx, where φ is the scalar potential. The dispersion relations obtained in the present work have been successfully compared with the theoretical and experimental work of several authors.     

Surface plasmon dispersion for very small metallic spheres: A quantum mechanical formulation

We have derived a pair of matrix equations describing the surface plasmon dispersion for a very small spherical metal particle, using the quantum mechanical random-phase approximation (RPA). The surface of the sphere is represented by an infinite spherical potential well for the conduction electrons and the positive ions are assumed to be uniformly distributed into a “jellium”. The dispersion relation is obtained as the condition that a solution of the RPA integral equation for charge fluctuation would exist for the particle.     

Surface plasmon in a parallel magnetic field

Using a hydrodynamic model the dispersion relation for the surface plasmon is calculated in an external magnetic field parallel to the surface when the wave propagates perpendicular to the magnetic field. In the limit of zero wave vector, the results reduce to those of Chiu and Quinn who have used the dielectric constant in the local theory.     

Effect of longitudinal excitations on surface plasmons

The influence of a longitudinal component in surface plasma waves propagating along the boundary between a plasma and vacuum has been investigated theoretically. It is found that the inclusion of the longitudinal component significantly modifies the dispersion relation for surface plasmons. In particular, it is shown that a surface plasmon can have any frequency in the interval from zero to the bulk plasma frequency.     

Observation of surface plasmon splitting on Ag(111) by electroreflectance spectroscopy

The spectral dependence of electroreflectance near the surface plasma frequency of Ag(111) has been measured for various degrees of surface roughness. The experiments clearly show a splitting of the surface plasma resonance on increasing the roughness of the sample. The results agree well with a recent theory which predicts a splitting of the surface plasmon dispersion relation on a statistically rough surface.     

Duality of Spoof Surface Plasmon Polaritons on the Complementary Structures of Ultrathin Metal Films

Complementary metal structures manifest a remarkable scattering feature, known as Babinet's principle. Meanwhile, for surface modes confined to one or two dimensions, the relation between the modes on complementary structures has not been thoroughly studied. Here, spoof surface plasmon polaritons supported on complementary metal films are systematically investigated. The duality of electromagnetism guarantees that these surface modes on complementary metal films possess precisely the same dispersion regardless of the geometry of the grooves, which is confirmed by both numerical simulations and experimental measurements. This work may open another avenue for spoof surface plasmon polaritons in both the theoretical and practical aspects.