Dynamic Potential of Interaction between Nitrogen Atoms and Aluminum Crystal Surface

Specific features of the angular distributions of accelerated neutral nitrogen atoms at the grazing angles of incidence on the Al(001) crystal surface have been investigated by the computer simulation method. The N–Al pair interaction potential is approximated by the three-parameter Morse potential with the energydependent coefficients. The angular distributions of scattered atoms have been simulated taking into account the interaction between atoms and several atomic layers in the lattice and the atomic displacement during thermal oscillations. The parameters of the pair potential of accelerated neutral nitrogen atoms in the energy range from 10 to 70 keV have been determined according to the best agreement between the calculated dependence of the rainbow scattering angle on the energy of particles incident on the crystal surface and the available experimental data.

     

Interaction of Gallium Atoms with the Surface of the Quartz Cell

The process of interaction of gallium atom vapors with the walls of a quartz cell was spectroscopically investigated. It has been shown that at high temperature (~1080°C) the process of diffusion of gallium atoms into the walls of the cell prevents to reach the densities of the metal vapors in the cell corresponding to the table values for given temperature. After saturation the cell walls by the metal atoms, the density of metal vapor in the volume of the cell increases.     

Study of the Interaction of Potassium Atoms with the Sapphire Surface with the Use of an Ultrathin Spectroscopic Cell

JETP Letters - The effect of the dielectric surface on the 39K D1 line (Fg = 1, 2 → Fe = 1, 2 transitions) at nanometer distances has been experimentally studied for the first time. A...     

Rainbow Scattering of Inert Gas Atoms on Aluminum and Silver Crystal Surfaces

Journal of Experimental and Theoretical Physics - Particle trajectories are calculated to study the rainbow scattering and the focusing of Ar atoms on the Al(111) and Ag(111) crystal surfaces and...     

耦合三能级原子与光场相互作用中系统的动力学行为

讨论了包含两个全同的三能级原子之间偶极矩相互作用的Jaynes-Cummings模型，并就Λ，Ξ和V三种能级构型建立了系统的动力学方程，特别在能级简并情况下讨论了具有Λ型能级的两个原子之间偶极相互作用及原子的初态和系统的失谐量对光场的统计性质和原子行为的影响。     

Absorption Spectra of Metal Atoms Adsorbed on the Surface of a Single Crystal

A method for obtaining the spectra of atoms adsorbed on a single crystal with an ion-covalent bond is suggested. A photostimulated burst of luminescence is used to record the spectra. The atoms are deposited in a vacuum by a mass-spectrometric technique. The absorption spectrum of silver atoms adsorbed on a silver chloride single crystal at concentrations comprising a millionth fraction of the surface monolayer has been obtained. It has been revealed that the optical ionization potential of an adsorbed silver atom is equal to 1.9 eV.     

Interaction of the Light Field with N Atoms Possessing Dipole-dipole Interaction

The interaction of the light field with two-level atoms possessing dipole-dipole interaction is studied. It is shown that a light field at coherent state can produce a squeezed atom laser.     

Interaction of the Light Field with N Atoms Possessing Dipole-dipole Interaction

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双模腔场－两原子系统中原子和场的动力学特性

研究了关联双模ＳＵ（１，１）相干态与两个二能级原子的相互作用过程中原子的崩溃与回复效应、辐射场的双模压缩和高阶双模压缩、以及光场的两模之间的非经典相关性质，详细讨论了原子间的偶极相互作用对它们的影响。     

Interaction of Negative Binomial States with Two-Level Atoms

We study the interaction of negative binomial states with two-level atoms. The dynamical evolutions of atomic population inversion, field entropy, Q function, and phase distribution are investigated in detail. The field becomes a superposition of negative binomial states at certain times, and this is confirmed further by its photon number distribution.     

两能级原子与热辐射场Raman相互作用时原子量子态保真度

两个两能级原子置于热辐射场环境中,原子用泡利算符描述,环境用无穷的谐振子热库描述.原子与热库产生Raman相互作用,原子间存在偶极相互作用,运用密度矩阵方法,得到两能级原子密度矩阵元演化规律.针对四种不同的初始状态,分析置于热辐射场中原子量子态保真度.结果表明:两个原子初始处于不同量子叠加态,量子信息在传输过程中的保真度有明显的差异.     

Features of the Radiation-Stimulated Hydrogenation of an Aluminum Surface

By the methods of reflection-absorption IR (infrared) spectroscopy, electrical measurement and AFM microscopy, the process of the radiation-stimulated hydrogenation of the aluminum surface in the Al/ads n-hexane system under γ-irradiation at room temperate is studied. On the basis of the dose dependence of the Al surface specific resistance, two stages of the hydrogenation process in the absorbed dose range (0.5?120 kGy) are revealed. It is established that the transition from the first to the second stage is accompanied by a decrease in the electrical conductivity of Al by 35 times and an increase in the hydride-nanolayer thickness by an order of magnitude. AFM studies of the aluminum surface relief showed that radiation-stimulated hydrogenation is accompanied by the formation of carbon-nanotube structures. A possible mechanism for the radiation-stimulated hydrogenation of aluminum is suggested.     

硼、氮取代二聚苯中碳原子导致层间相互作用本质变化研究

在MP2/aug-cc-pVTZ水平下优化了二聚苯及其碳被硼、氮原子取代的几何构型;计算了这些二聚体的CCSD(T)/CBS相互作用能;并用SAPT2+/aug-cc-pVDZ分析了相互作用能成分.探索了硼、氮取代二聚苯中碳原子所导致层间相互作用本质变化.结果表明:稳定构型而言,从苯(C_6H_6)、1-氮-2-硼杂苯(BNC_4H_6)、1,3-二氮-2,4-二硼杂苯(B_2N_2C_2H_6)二聚体的平行移位(PD)构型向无机苯(B_3N_3H_6)二聚体的夹心(S)构型转变,其中C_6H_6和B_3N_3H_6二聚体稳定构型的堆叠型式分别与之相对应的石墨烯(GE)和六方氮化硼(h-BN)2D层间材料的堆叠型式相一致.硼、氮原子取代二聚苯中的碳原子后使其相互作用能增大,其中BNC_4H_6和B_2N_2C_2H_6二聚体的相互作用能增大较为明显.所研究体系二聚体稳定构型均以色散能为主导、静电能次之、诱导能相对较小.硼、氮取代二聚苯中碳原子后其静电能对总吸引能的贡献明显增大.     

Thermodynamic Functions of a Crystal with Neutral Excited Atoms in the Lattice

The results obtained from a theoretical study on the thermodynamic functions (internal energy, heat capacity, entropy, and free energy) of a model crystal with neutral excited atoms in its lattice under low and high temperature conditions are discussed.__________Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 36–41, March, 2005.     

Quantum Treatment of the Interaction Between an N-Level Atom and Two Noninteracting Two-Level Atoms

We consider the problem of two two-level atoms interacting with N-level atom. We obtain the exact solution for the wave function for the case where both atoms are identical and the system is treated at exact resonance. We use the results obtained for discussing the temporal evolution of the atomic inversion, in particular, the collapse and revival phenomena. We build up our discussion on the variation of the atomic number j and the atomic angle θ. For small j, the system exhibits a small period of collapse, and for large j we observe a long period of revival. We employ the linear entropy in the discussion of entanglement. We show that the atomic angle θ influences the system in such a way that the period of partial entanglement increases with increase in the value of θ. In addition to the variance squeezing, we also examine the entanglement between the spinors and show that the squeezing phenomenon occurs in the second quadrature, being absent in the first quadrature. Also we realize that the squeezing phenomenon reaches its maximum and gets more pronounced for a small value of the atomic number and a large value of the atomic angle.     

Enhanced Quantum Reflection of Ultracold Atoms with Strong Interatomic Interaction

We calculate the reflection probability for ultracold alkali atoms incident on a solid surface. By considering the interatomic interaction and using the WKB method, it is shown that the repulsive interaction between atoms has the effect of increasing the reflection probability. The increasing amplitude is related with the interatomic interaction and the depth of atom-surface potential. In addition, we also perform a numerical calculation to testify the effect of the interatomic interaction, and the analytic result is proven by the numerical result.     

单模辐射场与N个原子相互作用理论

用玻色算符的三维型哈密顿量描述单模辐射场与Ｎ个两能级原子的相互作用。在原子系统处于低能态。光子数很大的初始条件下，得到了作用系统的动力学变化规律。     

Dynamic Strength of a Titanium Alloy with an Electron-Beam-Modified Surface

Data are presented of plane-wave experiments aimed at determining the dynamic strength of 3M titanium alloy with a surface processed by a microsecond electron beam. It has been found that the dynamic strength of processed specimens is higher than that of unprocessed specimens. Metallographic examination of test specimens has revealed spallation macrofracture inside the unprocessed specimens and spallation microfracture at the interface between the hardened layer and the substrate in the beam-processed specimens.     

Electron Impact Ionization Cross Section of Nitrogen Atoms

The direct ionization cross sections for electron scattering by nitrogen are calculated by applying an equivalentlocal optical model from 15eV to 1100eV. The present results are compared with the experimental data and other theoretical calculation results.     

动力学压缩真空与原子间偶极-偶极力

利用Milonni源理论方法研究了动力学压缩真空中两原子间偶极-偶极(d-d)相互作用力的性质与真空压缩的关系.结果发现:由于真空压缩的存在,两原子间d-d吸引力将受到削弱.当压缩系数为零时,得到通常文献中所熟知的结果.