共查询到20条相似文献,搜索用时 203 毫秒
1.
S.V. Kukhlevsky M. Mechler O. Samek K. Janssens 《Applied physics. B, Lasers and optics》2006,84(1-2):19-24
We present an analytical model of the resonantly enhanced transmission of light through a subwavelength nm-size slit in a
thick metal film. The simple formulae for the transmitted electromagnetic fields and the transmission coefficient are derived
by using the narrow-slit approximation and the Green’s function formalism for the solution of Maxwell’s equations. The resonance
wavelengths are in agreement with the semi-analytical model [Y. Takakura, Phys. Rev. Lett. 86, 5601 (2001)], which solves
the wave equations by using the Rayleigh field expansion. Our formulae, however, show great resonant enhancement of a transmitted
wave, while the Rayleigh expansion model predicts attenuation. The difference is attributed to the near-field subwavelength
diffraction, which is not considered by the Rayleigh-like expansion models.
PACS 42.25.Bs; 42.65.Fx; 42.79.Ag; 42.79.Dj 相似文献
2.
G. Czajkowski 《Il Nuovo Cimento D》1987,9(12):1545-1549
Summary The Stahl’s polariton equations for crystals, influenced by a uniform electric field, can be solved by means of an appropriate
Green’s function. The Green’s function is calculated for the half-space geometry and the field directed along the z-axis.
Using its asymptotic form a formula for the excitonic susceptibility is derived. 相似文献
3.
An explicit expression is obtained for the single-particle Green’s function of a 2D metallic system with attraction between
carriers. It is shown that as a result of transverse phase fluctuations, this function is pole-free throughout the entire
region of finite temperatures (both above and below the topological phase transition point) corresponding to a nonzero modulus
of the complex order field describing the transition from a nonsuperconducting (in this case normal) state to a superconducting
state, whose appearance in the 2D case is not accompanied by spontaneous breaking of charge symmetry.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 2, 126–131 (25 January 1999) 相似文献
4.
This paper presents a more detailed interaction of an electromagnetics light with a metallic surface-relief subwavelength grating utilizing the rigorous coupled-wave analysis. The focus of this work is the accurate modeling of undetermined aspects of diffraction patterns produced by binary metallic grating structures, specially gold grating. First-order diffraction efficiency for rectangular-groove gold grating with equal groove and ridge widths are presented for various wavelengths as a function of period, groove depth, polarization and angle of incidence. We also studied diffraction efficiency of both of TE and TM polarization modes against increasing of incident angle as well as TE polarization against increment of grating period. As a result, very low reflectivity at zero-order was found out for TE and TM polarizations at the pitch of Λ = 2λ. Having been studied diffraction efficiency of metallic surface-relief gratings, we also examined polarization-dependent efficiency of diffraction orders, for different groove depths. Simulation results have been completely presented. 相似文献
5.
Majid Rasouli Disfani Keivan Vafi Mohammad Sadegh Abrishamian 《Applied Physics A: Materials Science & Processing》2011,103(3):765-769
The dyadic Green’s function of a PEMC cylinder is derived with the aid of the principle of scattering superposition and Ohm–Rayleigh
method. The PEMC boundary conditions are presented in dyadic form and it shows that how the impedance parameter of PEMC and
cross-polarized fields appear in the Green’s function. The asymptotic expansions of the dyadic function is calculated in order
to attain a closed form for the electrical field. 相似文献
6.
R. Farchioni G. Grosso G. P. Parravicini 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,84(2):227-233
We study the electronic transmission of a model system composed by two coupled chains with an impurity attached to one of
them. Analytical espressions for the transmittivity and for the diagonal and the off-diagonal Green’s function matrix elements
are derived. Green’s function behaviour as function of the charge carrier energy is exploited to interpret the system transmittivity
calculated by the scattering matrix formalism. We find that while a single substitutional impurity in the ladder may generate
a Fano resonance in the transmittivity in the lower or in the higher energy part of the spectrum, in the case of a single side-attached impurity to the ladder, a resonance is found
in each energy region. We interpret such resonances in terms of local density of states and off-diagonal Green’s function matrix
elements. 相似文献
7.
A bound state in a continuum (BIC) might appear in open quantum dots for the variation in the dot’s shape. By means of the
equations of motion of the Green’s functions, we investigate the effect of strong intradot Coulomb interactions on that phenomenon
within the framework of the impurity Anderson model. The equation that the imaginary part of the poles of the Green’s function
equals zero yields the condition for BICs. As a result, we show that the Coulomb interactions replicate the single-electron
BICs into two-electron ones.
The text was submitted by the authors in English. 相似文献
8.
The method of calculating the electromagnetic wave field diffracted by a holographic grating with a multilayer dielectric
coating is developed. The method consists of the representation of the field inside dielectric layers in the form of a plane-wave
expansion for weakly damped harmonics and an expansion over functions of the concomitant coordinate system for strongly damped
orders. This modification of the method allows calculation of the diffraction efficiency and the electric field strength for
the deep groove gratings. It is shown that a diffraction element that possess high efficiency and radiation strength can be
obtained even when the profile of the dielectric layers flattens with an increase in the distance from the grating’s metallic
layer. 相似文献
9.
Spectral functions in the two-dimensional
Hubbard model within a spin-charge rotating frame approach
T. A.?Zaleski T. K.?Kope? 《The European Physical Journal B - Condensed Matter and Complex Systems》2010,76(3):405-419
We have performed electronic spectral function calculations for the Hubbard model on the square lattice using recently developed
quantum SU(2) × U(1) rotor approach that enables a self-consistent treatment of the antiferromagnetic state.
The collective variables for charge and spin are isolated in the form of the space-time fluctuating U(1) phase field and rotating
spin quantization axis governed by the SU(2) symmetry, respectively.
As a result interacting electrons appear as composite objects consisting of bare fermions with attached U(1) and SU(2) gauge
fields.
This allows us to write the fermion Green’s function in the space-time domain as a product of the SU(2) gauge fields, U(1)
phase propagator and the pseudo-fermion correlation function.
Consequently, the calculation of the spectral line shapes now reduces to performing the convolution of spin, charge and pseudo-fermion
Green’s functions.
The collective spin and charge fluctuations are governed by the effective actions that are derived from the Hubbard model
for any value of the Coulomb interaction.
The emergence of a sharp peak in the electron spectral function in the antiferromagnetic state indicates the decay of the
electron into separate spin and charge carrying particle excitations. 相似文献
10.
B. N. Libenson 《Journal of Experimental and Theoretical Physics》2012,114(2):194-204
The Green’s function of the electric field of plasmons is determined in a semi-infinite medium with an abrupt plasma boundary
where nonequilibrium conduction electrons either undergo elastic reflection from the boundary or “stick” to it and give rise
to a stationary surface charge. The angular reflection of elastically scattered electrons can be either specular or diffuse.
The Green’s function is used to find the singleevent spectrum of energy loss by a fast electron moving parallel to the boundary.
The effect of electronboundary scattering parameters on the structure of bulk and surface plasmon resonances is analyzed.
The probability of transition radiation of bulk plasmon by an electron moving in vacuum is examined. A new type of surface
resonance is found under conditions of perfectly elastic scattering of conduction electrons from the plasma boundary, similar
in structure to a tangential surface plasmon. 相似文献
11.
E.V. Ponizovskaya A.M. Bratkovsky 《Applied Physics A: Materials Science & Processing》2007,87(2):175-179
Arrays of metallic nanoparticles support individual and collective plasmonic excitations that contribute to unusual phenomena
like surface-enhanced Raman scattering, anomalous transparency, negative index, and subwavelength resolution in various metamaterials.
We examined the electromagnetic response of dual Kron’s lattice and films containing up to three monolayers of metallic nanospheres.
It appears that open cubic Kron’s lattice exhibits ‘soft’ electromagnetic response but no negative index behavior. The close-packed
arrays behave similarly: there are plasmon resonances and very high transmission at certain wavelengths that are much larger
than the separation between the particles, and a ‘soft’ magnetic response, with small but positive effective index of refraction.
It would be interesting to check these predictions experimentally.
PACS 78.20.Ci; 42.30.Wb; 73.20.Mf; 42.25.Bs 相似文献
12.
X. Ni G. V. Naik A. V. Kildishev Y. Barnakov A. Boltasseva V. M. Shalaev 《Applied physics. B, Lasers and optics》2011,103(3):553-558
Spontaneous emission patterns of electric and magnetic dipoles on different metallic surfaces and a hyperbolic metamaterial
(HMM) surface were simulated using the dyadic Green’s function technique. The theoretical approach was verified by experimental
results obtained by measuring angular-dependent emission spectra of europium ions on top of different films. The results show
the modified behavior of electric and magnetic dipoles on metallic and HMM surfaces. The results of numerical calculations
agree well with experimental data. 相似文献
13.
金属薄膜亚波长微结构的光束集束器件设计 总被引:1,自引:0,他引:1
利用时域有限差分方法,模拟了P偏振光高斯光束入射到金属银亚波长细缝与光栅结构的透射情况.由于表面等离子激元波的影响,对称光栅结构透射光呈现对称出射,而非对称结构可以实现小角度定方向的光束集束现象.借助公式推导法及Helmholtz互易定理,可设计出平行入射P偏振光的光束集束器件.由于高斯光束本身的发散性及近场分布的需要,针对高斯光束的器件在结构参量上缩小了12%.在对其他结构参量的优化的基础上,实现了针对633 nm高斯光束的对称出射及光束集束器件的设计. 相似文献
14.
A. A. Abrikosov Jr. 《JETP Letters》1996,63(11):869-872
Scalar matter in an instanton field in a closed volume is studied. A compact expression is found for the exact Green’s function
of massless scalar particles in the fundamental representation.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 11, 833–836 (10 June 1996) 相似文献
15.
16.
Simple nonintersecting thin metallic wire photonic crystals are studied using the integral equation method based on the Green’s
function for periodically arranged sources. A wavenumber- and wavevector-dependent effective permittivity tensor is derived
upon homogenization, and the band diagram and the per-mittivity for the lower dispersion branch are calculated. 相似文献
17.
In this work, the amplitude of the interaction of an electromagnetic field with π-mesons has been determined in the context
of a relativistic gauge-invariant approach by solving electrodynamic equations with the use of the covariant Green’s function
method. Based on this approach, the effective Lagrangian of the two-photon interaction with spin-0 hadrons taking into account
the electric and magnetic polarizabilities has been obtained. 相似文献
18.
Electromagnetic Diffraction Analysis of 2-D Antireflective Subwavelength Grating with Coned Profile 总被引:2,自引:0,他引:2
1 Introduction Itiswellknownthatconventionalmethodsof producingextremelybroadbandantireflectivesurfacesarelimitedintheinfraredregion ,becauseofthelimitednumberofthin filmcoatingmaterialsavailableforusetoday .Subwavelengthsurface relief gratingshavebeenr… 相似文献
19.
2D subwavelength multilevel (2-, 4-, 8-, etc. levels) columned stairstep grating with coned spatial profile has been designed to reduce reflection. In this paper, the rigorous coupled-wave theory is employed to analyze the electromagnetic diffraction property of the columned stairstep grid grating. The structure is shown to achieve extremely low reflectance over a wide field of view and a wide light wave band. 相似文献
20.
V. A. Kosobukin 《Physics of the Solid State》2009,51(2):400-408
In terms of Green’s functions, a theory is developed describing the resonant magnetooptical Kerr effect in light scattering
by a linear probe that is parallel to the surface of a magnet and placed at a subwavelength distance from it. The probe is
supposed to be a metal nanowire supporting long-lived surface plasmons and forming the near field of the “probe + image” complex.
The resonant interaction between the probe and the sample is taken into account within a self-consistent approximation of
multiple-scattering theory, and the magnetooptical interaction is included in the linear approximation in magnetization. The
problem of scanning near-field magnetooptical microscopy with a linear probe is solved analytically in the case where the
magnetization is parallel to both the magnet surface and the plane of incidence of light (longitudinal magnetooptical Kerr
effect). The polarization, spectral, and angular characteristics of scattered light modulated by magnetization are discussed.
It is shown that the magnetooptical modulation of the scattered light intensity is significantly enhanced when surface plasmons
are resonantly excited in the nanowire. 相似文献