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.     

Fermi-liquid relations, large-N expansion and Bethe-ansatz solution for the degenerate Anderson model

The large-N expansion results for the ground-state charge and spin susceptibilities are compared with the exact Bethe-ansatz solution. The agreement is good in the mixed-valence regime and poor in the Kondo limit. The exact Fermi-liquid relation between the T-linear coefficient of the specific heat and the spin and charge susceptibilities is derived and compared with the results within the large-N approximation.     

Charge distribution in a MIS insulator from spectral characteristics of photoemission current

The field dependence of photoemission currents in a MIS structure was derived for the case when the space charge is randomly distributed over the insulating layer. It was found analytically that the position of the top of the potential barrier for electrons photoinjected from the gate into the insulator is defined by the derivative of this barrier with respect to the external field strength. A method for correctly determining the space charge profile in a MIS insulator is suggested. The profile is derived from a family of spectral characteristics taken at different gate voltages. The method is especially suitable for profiling the negative charge in MIS insulators.     

d Orbital doping into pi charge-ordered molecular insulator

A quasi-one-dimensional pi-electron charge-ordered insulator, (DI-DCNQI)2Ag, is metallized by Cu doping into the Ag sites. It is found that with doping the charge gap is diminished and then disorder-induced insulating nature comes up, eventually followed by transition or crossover to a pi-d networked metal. The profile of the charge-gap collapse is consistent with the prediction of the theory highlighting the interplay between electron correlation and disorder. The present doping method is regarded as doping of d orbital, which is different from the conventional charge and/or spin doping developed in cuprates and manganites.     

金属电极与分子中非弹性电流的理论研究

考虑分子的振动能级,在简正反应坐标下研究了通过"金属/分子/金属"所组成系统的非弹性电流.研究发现非弹性电流传输过程中分子不同带电态的能量的相对位形对Franck-Condon阻滞有较强的影响,进而在理论上分析了分子的稳定态与Franck-Condon阻滞的关系,以及分子内部的振动能量分布、分子与金属电极的相对位置与系统的电流-电压曲线的关系.     

On the Newton-Coulomb unification

The full geometry surrounding a point particle in an empty five-dimensional universe is derived. The Newton and the Coulomb laws are unified via a generalized Reissner-Nordstrøm geometry, with the electric charge resembling a topologically-frozen boost. The ratio of the compactification radius to the Schwarzschild radius is the key parameter in a novel mass/charge relation. Mini black holes, owing their entire mass to the electromagnetic interaction, are discussed.     

Coherence effects in S/I/N/I/FS tunnel junctions

The dc Josephson effect in superconductor / insulator / normal metal / insulator/ferromagnetic superconductor junctions has been studied. We calculate the de Josephson current based on the Bogoliubov de Gennes equation. The Josephson current is derived as a function of exchange field in ferromagnetic superconductor, normal metal thickness and insulating barrier strength. It is found that there exists an oscillation relation between the critical Josephson current and the normal metal thickness. The oscillation amplitude decreases as the thickness of the normal metal increases or the exchange field augments.[第一段]     

介观金属双环系统中的持续电流和量子能谱

基于电荷的不连续性,对处于外磁场中的介观双环系统进行量子化.假设系统在电荷表象中具有变换的对称性,通过求解电流和Hamilton算符的本征值方程,给出介观金属环互感系统中的量子电流和能谱关系;分析和研究了介观金属环中量子电流和能谱的性质.结果表明,持续电流和量子能谱不仅与外磁场、介观双环参数有关,而且还明显地依赖于电荷的量子化性质.     

JB-9001钝感炸药冲击Hugoniot关系测试

 利用“压力对比法”实验技术，通过锰铜压力计测试待测炸药样品和LY12铝样品在LY12铝飞片的同时撞击下的界面压力p_exp和p_Al，从冲击波关系式和正交回归直线拟合分析，确定了JB-9001钝感炸药的冲击Hugoniot关系。     

Thermoelectric power of mixed electronic-ionic conductors I. Basic equations

The present work considers thermopower of oxide materials within n-p transition regime. Specifically, basic equations describing the effect of thermocell reactions on both ionic and electronic component of thermoelectric power are derived. The proposed formalism considers the impact of gas/solid reactions on the relationship between thermopower and electrochemical potential within a system involving a metal oxide of nonstoichiometric composition and a metal (such as Pt) that is applied as a measuring electrode. The derived theoretical model allows the determination of the thermopower components corresponding to different charge carriers, including ions, electrons and electron holes, for metal oxides. The proposed model may be used for derivation of defect chemistry models based on thermopower data that are free of the ionic component.     

Surface waves of the potential type at the interface between a metal and an inhomogeneous medium

A study is made of surface waves of the potential type propagating along the interface between a metal and a plasma of nonuniform density, with the thermal motion of the electrons taken into account. Dispersion relation for these waves are derived and solved for a linear plasma density profile. The influence of the nonuniformity of the plasma density on the dispersion properties of the waves is studied. Cases of negative and positive gradients are considered. Zh. Tekh. Fiz. 69, 80–83 (July 1999)     

超导体/正常金属/半导体/正常金属/超导体结的研究

在约瑟夫逊效应的理论研究中,大体上有微观和宏观两种方法。采用的是宏观的方法。利用推广的Ja-cobson方法,讨论了超导体/正常金属/半导体/正常金属/超导体结的约瑟夫逊效应,并在小电流假设下,推导出了该结的电流密度与位相之间的关系。     

Density functional simulation of interfacial relaxation and capacity of a model metal/electrolyte interface

A “jellium”-type model for an interface between s-p metal and a solution of surface inactive electrolyte is used to simulate its structure and electric properties. The effect of the electrode charge on the surface electronic profile and the equilibrium distance of the closest approach of solvent molecules to the ionic skeleton of the metal is studied using density functional variational method. Both the profile decay length and the closest approach distance are subject to variation. Interfacial relaxation is found to be of crucial importance in the capacity-charge plots giving rise to their new interpretation.     

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.     

Self-consistent theory of cyclotron autoresonance maser in a uniform planar waveguide

A general dispersion relation for the cyclotron autoresonance maser (CARM) that takes into account self-consistent couplings between TE, TM and ac space charge perturbations in a uniform planar waveguide is derived. The dispersion relation predicts enhanced growth rate due to ac space charge effects. Results from computer simulations of a planar CARM amplifier are presented to support this finding.     

Long range correlations in DNA: scaling properties and charge transfer efficiency

We address the relation between long-range correlations and charge transfer efficiency in aperiodic artificial or genomic DNA sequences. Coherent charge transfer through the highest occupied molecular orbital states of the guanine nucleotide is studied using the transmission approach, and the focus is on how the sequence-dependent backscattering profile can be inferred from correlations between base pairs.     

Dust lattice wave dispersion relations in two-dimensional hexagonal crystals including the effect of dust charge polarization

A dusty plasma crystalline configuration with equal charge dust grains and mass is considered. Both charge and mass of each dust species are taken to be constant. Two differential equations for a two-dimensional hexagonal crystal on the basis of a Yukawa-type potential energy and a “dressed” potential energy, accounting for dust charge polarization, are derived and compared. The dispersion relation for both longitudinal and transverse wave propagation in an arbitrary direction is derived. A comparison to analytical and experimental results reported previously is carried out.     

Relationship between the auger parameter and the energy gap

In this communication we show that for different semiconductors which do not contain transition metal ions, the shift in the extra-atomic relaxation energy for the metal ion with the core hole-as measured by the Wagner Auger parameter shift with respect to the metallic state-is roughly linearly correlated to the energy gap with a slope approximately equal to −1. The relationship, useful from a practical point of view, can be rationalized using the qualitative concepts of local and non-local screening developed by Veal and Paulikas and the direct relation between the band gap and anion electronegativity.

The core-hole screening for the semiconductors that follow the correlation can be described by the non-local screening mechanism. In this case, the polarized ligands transfer electronic charge to the unfilled s-p metal orbitals which are pulled down to the energy level of the local anion valence band by the core hole. Semiconductors containing transition metal ions, for which local screening mechanisms can occur by transferring the charge from the ligands to the localized d electronic levels, do not follow the correlation. This is due to the fact that the Auger parameter of the cation in the compound is similar to that of the atom in the metallic state. This result indicates that the relaxation energy in the transition metal compounds can be similar to the screening energy in the metallic state.     

金属的高能二次电子发射系数与入射能量和能量幂次的关系

 根据原电子射程表达式和金属的有效真二次电子发射系数表达式,推导出金属的高能有效真二次电子发射系数与入射能量、能量幂次的关系式;并根据金属的高能有效真二次电子发射系数与金属的高能二次电子发射系数的关系,推导出金属的高能二次电子发射系数与入射能量、能量幂次的关系式。用实验数据计算出高能原电子轰击在金或银上时原电子入射能量幂次n,采用实验数据证实高能二次电子发射系数与原电子入射能量和能量幂次三者的关系,对结果进行讨论并得出结论：当高能原电子轰击在同一块金属上时,高能二次电子发射系数与原电子入射能量的n-1次幂之积近似为一常数。     

Derivation of the radial distribution function from experimental Compton profiles

The analysis of experimental Compton profiles in position rather than momentum space provides a useful method of interpreting Compton data. A density matrix approach is employed to establish the relationship between the Compton profile J(p), and the Fourier transform of the momentum density B(r), and, for a homogeneous system, the radial distribution function g(r). An earlier Compton profile measurement on sodium provides the data for a demonstration of the long range charge correlations in a metal, in analogy with the Friedel oscillations in a screening charge.