共查询到20条相似文献,搜索用时 0 毫秒
1.
N.N. Beletskii Y.V. Bludov 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):331-334
The paper deals with the theoretical investigation of nonlinear surface polaritons (NSP) in isolated two-dimensional electron
system (2DES) arranged at the interface between linear and nonlinear media and placed into the external quantizing magnetic
field directed perpendicularly to 2DES. We consider that nonlinear medium dielectric permeability depends upon the tangential
component of electric field only. It is shown that under the integer quantum Hall effect conditions all NSP characteristics
are represented by the quantized values. It is found that the NSP spectrum contains two NSP modes - high-frequency and low-frequency
ones. It is shown that the NSP can exist only in the case where the value of tangential component of electric field at the
interface is less than a certain critical value. It is found that the resonant interaction between the NSP high-frequency
mode and surface polariton mode occurs in the vicinity of the cyclotron resonance subharmonic.
Received 23 September 2001 / Received in final form 31 January 2002 Published online 2 October 2002
RID="a"
ID="a"e-mail: bludov@ire.kharkov.ua 相似文献
2.
J.M. Pereira Jr. R.N. Costa Filho V.N. Freire G.A. Farias 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,3(1):119-123
The resonance properties of localized electrostatic surface modes associated with a finite number of ridges on an otherwise
planar surface are investigated. Numerical solutions of the homogeneous integral equations that describe the electromagnetic
fields in the vicinity of the ridges are used to obtain the dispersion relation of surface plasmons. The frequencies of the
electrostatic surface shape resonances are calculated for ridges with Gaussian, Lorentzian, sinusoidal, exponential, and triangular
profiles. We show the existence of splittings of the plasmon frequencies, which depends on the surface profile function and
on the distance between the ridges. Considering the ridge with a sinusoidal profile, we obtain the limit on the number of
ridges which generates a frequency splitting of the electrostatic surface shape resonances, whose frequency values converge
to those of the dispersion relation of surface plasmons on one-dimensional sinusoidal grating.
Received: 24 June 1997 / Received in final form: 5 September 1997 / Accepted: 15 September 1997 相似文献
3.
J.M. Pereira R.N. Costa Filho V.N. Freire G.A. Farias 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,13(3):589-593
The spectrum of surface shape resonances associated with a finite number of ridges on one interface of an otherwise plane
film is calculated. The frequencies are obtained numerically by solving the homogeneous integral equations which describe
the electrostatic field in the vicinity of a surface defect. The calculations are performed for a surface with ridges with
Gaussian, Lorentzian and sinusoidal profiles. The results show a strong dependence of the localized plasmon frequencies on
the surface profile, on the distance between the ridges, and on the thickness of the film.
Received 5 April 1999 and Received in final form 6 July 1999 相似文献
4.
A.A. Raduta E. Garrido E. Moya de Guerra 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(1):65-77
Some properties of small sodium clusters, comprising up to 45 atoms, are described using a projected spherical single particle
basis. The variation of the cluster shape and inner density with the number of atoms is studied. Seemingly chestnut, clusterization
and halo like structures are identified for several metallic clusters. Static polarizabilities and plasmon frequencies are
calculated and compared with experimental data and with results obtained in different approaches.
Received 28 November 2000 and Received in final form 15 February 2001 相似文献
5.
Vl.A. Margulis S.V. Makarov T.V. Piterimova E.A. Gaiduk 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,33(2):153-164
Using a mean-field approximation, we have developed a systematic treatment of collective electronic modes in a semiconductor
superlattice (SL) in the presence of strong electric and magnetic fields parallel to the SL axis. The spectrum of collective
modes with zero wavevector along the SL axis is shown to consist of a principle magnetoplasmon mode and an infinite set of
Bernstein-like modes. For non-zero wavevector along the SL axis, in addition to the cyclotron modes, extra collective modes
are found at the frequencies |Nω
c±Mω
s|, which we call cyclotron-Stark modes (ω
c and ω
s are respectively the cyclotron and Stark frequencies, N and M are integer numbers). The frequencies of the modes propagating in “oblique” direction with respect to the SL axis show oscillatory
behavior as a function of electric field strength. All the modes considered have very weak spatial dispersion and they are
not Landau damped. The specific predictions made for the dispersion relations of the collective excitations should be observable
in resonant Raman scattering experiments.
Received 29 August 2002 / Received in final form 25 February 2003 Published online 4 June 2003
RID="a"
ID="a"e-mail: 612033@inbox.ru 相似文献
6.
M.V. Moskalets 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,15(3):523-529
The peculiarities of a low temperature heat transfer through a ballistic quantum dot (a double potential barrier) with interacting
leads due to a long-range Coulomb interaction (in the geometrical capacitance approach) are considered. It is found that the
thermal conductance K shows periodic peaks as a function of the electrostatic potential of a dot at low temperatures. At the peak maximum it is
whereas near the minimum it is . Near the peak maximum the dependence K(T) is essentially nonmonotonic at the temperatures correspondent to the level spacing in the quantum dot.
Received 20 October 1999 and Received in final form 20 January 2000 相似文献
7.
Magnetic dipole and electric quadrupole responses of elliptic quantum dots in magnetic fields 总被引:1,自引:0,他引:1
E. Lipparini Ll. Serra A. Puente 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,27(3):409-415
The magnetic dipole (M1) and electric quadupole (E2) responses of two-dimensional quantum dots with an elliptic shape are
theoretically investigated as a function of the dot deformation and applied static magnetic field. Neglecting the electron-electron
interaction we obtain analytical results which indicate the existence of four characteristic modes, with different B-dispersion of their energies and associated strengths. Interaction effects are numerically studied within the time-dependent
local-spin-density and Hartree approximations, assessing the validity of the non-interacting picture.
Received 29 November 2001 Published online 6 June 2002 相似文献
8.
Y.I. Latyshev B. Pannetier P. Monceau 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,3(4):421-426
We demonstrate for the first time that a periodic array of submicrometer holes (antidots) can be patterned into thin single
NbSe3 crystals. We report on the study of Charge Density Wave (CDW) transport of the network of mesoscopic units between antidots.
Size of the elementary unit can be as small as 0.5 μm along the chain axis and in cross-section. We observe size effects for Ohmic residual resistance and in CDW transport current-voltage characteristics
in submicronic networks.
Received: 25 November 1997 / Received in final form: 30 March 1998 / Accepted: 6 April 1998 相似文献
9.
C. P. Pang J. T. Lue 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(4):593-600
The linear refractive indices and nonlinear second-order susceptibility of
hydrated and dehydrated silica micro-spheres are studied using attenuated
total reflectance (ATR) and the second harmonic generation (SHG) method in
direct transmission, respectively. A dramatic change of the effective
dielectric constant of silica suspension under an electric bias was
observed, which is attributed to particle redistribution in the fluid.
Dielectric constants of dehydrated silica spheres change slightly under an
electric field due to Pockels effect, for which we measure a linear
electro-optical coefficient of r33 ∼3.4±0.7 pm/V. The
transmission second harmonic generation comes from the third-order
susceptibility χ(3), which is a coupling of two photons and the
electrostatic field induced by the surface –OH charges as characterized by
the Gouy-Chapman model. The SH signal from the dehydrated silica vanishes
because of the loss of –OH groups on the particle surfaces. Dehydration of
silica beads is irreversible. The optical properties of dried silica spheres
do not recover their original hydrated state when distilled water is added. 相似文献
10.
K. Sabeeh N. J. M. Horing V. Fessatidis 《Physica E: Low-dimensional Systems and Nanostructures》2004,22(4):843-851
We have employed random-phase approximation to determine the inverse dielectric function for a harmonically confined two-dimensional electron gas in a magnetic field. We examine the plasmon dispersion relation and show the results for the variation of plasmon frequency with the magnetic field strength and confinement energy. 相似文献
11.
W.-Y. Ruan H.-F. Cheung 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,3(3):407-411
A coupled quantum dot system has been studied by numerical diagonalization of the Hamiltonian. Discontinuous ground-state
transitions induced by an external magnetic field have been predicted. Series of magic numbers of angular momentum which minimize
the ground-state electron-electron interaction energy have been discovered. Theoretical explanations derived from the first
principles have been formulated.
Received: 13 July 1997 / Accepted: 7 October 1997 相似文献
12.
Summary The FBA scattering cross-section in the presence of a strong magnetic field diverges at the Landau thresholds. Such divergences
are eliminated by the introduction of a modified density of states, accounting for the finite Landau states lifetime of the
electrons in a magnetized plasma. 相似文献
13.
M. Zarcone 《Il Nuovo Cimento D》1991,13(6):749-756
Summary The total cross-section for potential scattering in the presence of a strong magnetic field presents singularities and exhibits
giant growth (cyclotron resonances) at values of the incident particle energy exactly matching the differences between the
initial-and final-state Landau levels. In this paper (in cylindrical coordinates) a higher-order modified Born series has
been derived that can be summed at all orders giving a nondivergent total cross-section at the Landau thresholds. 相似文献
14.
Summary Scattering cross-sections, reflection and transmission coefficients are derived for charged-particle potential scattering
in the presence of a quantizing constant magnetic field within the Green's function approach. The optical theorem and the
limit of the cross-section for vanishing values of the magnetic field have also been obtained. A numerical analysis of the
total cross-section for different magnetic-field intensities and values of the screening constant has been performed. The
total cross-sections are found to differ significantly from the field-free ones only for magnetic-field intensities and incident
particle energies such that only few Landau channels are open.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献
15.
R. Lazzari I. Simonsen D. Bedeaux J. Vlieger J. Jupille 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,24(2):267-284
The light scattering by three-dimensional clusters supported by a substrate is modelled by representing clusters by truncated
spheroids whose polarizability is calculated via a multipolar development of the potential in the quasi-static limit. The determination of the mean island radius, density
and aspect ratio from the optical response is examined. The strong influence of both the particle-substrate interaction and
the particle shape on the optical behaviour is demonstrated, showing the limits of effective medium and dipolar theories.
The Surface Differential Reflectance spectra of silver on MgO(100) and titanium or aluminium on α-Al2O3(0001) surfaces have then been modelled by using the above model, illustrating the capability of optical means to deal with
various metals, including those belonging to transition series. In all cases, it is highlighted that the aspect ratio is central
in modelling the optical response of supported particles.
Received 5 June 2000 and Received in final form 31 July 2001 相似文献
16.
Y. C. Okada 《Il Nuovo Cimento D》1983,2(2):379-409
Summary Research in the evoked magnetic field reported in the last two years is reviewed. The studies have shown that the magnetic
technique may be used 1) to reveal complementary aspects of the current sources common to evoked potential, 2) to identify
the organization of the cerebral cortex and subcortical areas of the brain and 3) to measure functional properties of the
active neural areas whose locations are identified.
Paper presented at the ?IV International Workshop on Biomagnetism?, held in Rome, September 14–16, 1982. 相似文献
17.
Summary Bulk properties of the exciton-polariton dispersion in the presence of a uniform electric field and for frequencies near the
first excitonic resonance are studied within the framework of Stahl’s coherent band dynamics. A relative simple expression
for the excitonic susceptibility (and thus for the dispersion relation) is derived and applied for calculating the field dependence
of the transverse excitonic frequency. By an appropriate choice of a certain fitting parameter the calculated energy shift
agrees satisfactorily with experimental values obtained recently by Schultheis and K?hler.
Riassunto Si studiano le proprietà di massa della dispersione eccitone-polaritone in presenza di un campo elettrico uniforme e per frequenze vicine alla prima risonanza eccitonica, nell’ambito della dinamica di banda coerente di Stahl. Si deduce una semplice espressione relativa per la suscettività eccitonica (e quindi per la relazione di dispersione) e la si applica nel calcolo della dipendenza della frequenza eccitonica trasversa dal campo. Con la scelta appropriata di un adatto parametro lo spostamento di energia calcolato è in accordo in modo soddisfacente con i valori sperimentali ottenuti recentemente da Schultheis e K?hler.
Резюме В рамках когерентной зонной динамики Стахля исследуются объемные свойства экситон-поляритонной дисперсии в присутствии однородного электрического поля и при частотах вблизи первого экситонного резонанса. Выводится относительно простое выражение для экситонной восприимчивости (и, следовательно, для дисперсионного соотношения). Полученное выражение используется для вычисления зависимости поперечной экситонной частоты от поля. При соответсвующем выборе подгоночного параметра вычисленный энергетический сдвиг удовлетворительно согласуется с экспериментальными величинами, недавно полученными Шультесом и Кёхлером.相似文献
18.
C. Furtlehner 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,18(2):297-301
Localization of an electron moving in two dimensions, submitted to a strong magnetic field and scattered by randomly distributed
zero-range impurities is investigated. Considering the explicit expression for the density of states obtained by Brézin, Gross
and Itzykson, the Lifshitz argument is adapted in order to analyze the unusual power-law behavior of the low energy spectrum.
When the impurity density is smaller than the Landau degeneracy, typical configurations of disorder responsible for low energy
states are identified as cluster of impurities of well defined form. This allows for an interpretation of low-lying states,
localized around these clusters, whose size diverges logarithmically as the energy goes to zero.
Received 5 January 2000 相似文献
19.
J. Panicker G. Mishra U. S. Yadav K. P. Maheshwari G. P. Gallerano 《Il Nuovo Cimento D》1996,18(7):777-789
Summary In this paper we study the spectral brightness of the radiation emitted by electrons moving in longitudinal wiggler and solenoidal
magnetic field. The analysis is based on the evaluation of the Lienard-Wiechert potential retaining the condition of far-field
limit. Some features of a longitudinal wiggler are presented and compared with the results relevant to the brightness of the
helical wiggler and the solenoidal magnetic field employed in gyrotron-type devices. 相似文献
20.
I. Bâldea H. Köppel L.S. Cederbaum 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,20(2):289-299
We present a new effect that is possible for strongly correlated electrons in commensurate mesoscopic rings: the collective tunneling of electrons between classically equivalent configurations, corresponding to ordered states possessing charge and
spin density waves (CDW, SDW) and charge separation (CS). Within an extended Hubbard model at half filling studied by exact
numerical diagonalization, we demonstrate that the ground state phase diagram comprises, besides conventional critical lines
separating states characterized by different orderings (e.g. CDW, SDW, CS), critical lines separating phases with the same ordering (e.g. CDW-CDW) but with different symmetries. While the former also exist in infinite systems, the latter are specific for mesoscopic systems and directly related to a collective tunnel effect. We emphasize that, in order to construct correctly
a phase diagram for mesoscopic rings, the examination of CDW, SDW and CS correlation functions alone is not sufficient, and
one should also consider the symmetry of the wave function that cannot be broken. We present examples demonstrating that the
jumps in relevant physical properties at the conventional and new critical lines are of comparable magnitude. These transitions
could be studied experimentally e.g. by optical absorption in mesoscopic systems. Possible candidates are cyclic molecules and ring-like nanostructures of quantum
dots.
Received 27 November 2000 相似文献