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1.
本文基于无任何可调参数的势模型计算了碱土金属原子(Be、Mg、Ca、Sr、Ba)与Ne原子间相互作用势,得到的势能曲线及势阱位置和深度与现有的从头计算结果符合较好.本文的计算结果进一步验证了碱土金属原子与稀有气体原子间交换能主要来自碱土金属原子最外层s电子与稀有气体原子最外层p电子之间的交换作用. 相似文献
2.
通过考虑碱金属原子中的价电子在模型势中的运动, 给出了碱金属原子激发态(包括分立谱和连续谱)的波函数, 导出了碱金属原子的多极动态极化率的计算式中所涉及的矩阵元的解析表达式, 实现了碱金属原子多极动态极化率的解析计算. 作为应用, 利用范德瓦尔斯相互作用系数与动态极化率之间的积分关系, 计算了异核基态碱金属原子间的三体相互作用系数, 将计算结果与此前用稳定变分方法得到的结果进行了比较, 结果显示两者是一致的. 此工作为后续研究激发态碱金属原子间的相互作用奠定了基础. 相似文献
3.
利用碱金属原子的模型势和稳定变分法,首次计算了异核碱金属原子间的三体相互作用系数.为了说明计算结果的精度,同时计算了碱金属原子的电多级极化率.与其他作者的理论数据和有关实验数据的比较表明,本文所得到的异核碱金属原子间的三体相互作用系数是可靠的. 相似文献
4.
原子间相互作用势是预测惰性气体输运性质的必要输入条件. 文章对描述惰性气体原子间相互作用的Lennard-Jones势、指数排斥势、Hartree-Fock-Dispersion-B (HFD-B)势和唯象势的形式和特点进行了分析. 基于Chapman-Enskog方法, 计算得到了惰性气体在300–5000 K温度区间内基于四种原子相互作用势的黏性和热导率, 并与文献报道的实验和理论计算结果进行了比较. 研究结果表明, 基于Hartree-Fock排斥理论与色散理论发展起来的HFD-B势能够合理反映惰性气体原子相互作用的趋势与特征, 因而可以较好地预测惰性气体的宏观输运性质. 相似文献
5.
原子与分子间相互作用势能可一部分,一部分可表达为近程排斥势,另一部分则表达为远程吸引对这两种势能的表达方式和计算方法已有很多,此文主要对原子间远程吸引势采用pade近似处理法,从动态极化率来计算范德瓦尔斯系数,并进而计算吸引势,为惰性气体原子间远程势提供一个有效的计算方法。 相似文献
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用Drude模型和Born-Mayer势系统地研究了原子畸变效应对原子间相互作用的贡献。用Born-Mayer势描述了原子间由于相互重迭而引起的畸变效应,克服了GK-Drude方法的这一缺陷,提出了确定Born-Mayer势参数简单实用的方法。计算结果表明:Born Mayer势能相当准确地反映原子间由于相互重迭而引起的畸变效应;原子畸变效应对原子间的相互作用有重要的贡献。我们求得的惰性气体原子间的相互作用势,不仅改进了用GK-Drude方法求得的结果,而且与实验值符合得很好。 相似文献
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根据用我们提出的方法求出的惰性气体原子间的相互作用势,计算了惰性气体的粘滞系数和热传导系数,其结果与实验值符合得很好,相对误差都在3%以下。证实了我们提出的计算原子间相互作用势的方法的准确性。 相似文献
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作为构成量子多体系统的基本单元,一维少体系统的研究不仅可以在理论上为多体系统的量子关联及动力学等性质提供更为基本的理解,也可以为实验上制备多体系统提供更加方便和功能更加全面的方法.本文回顾了冷原子物理中一维少体系统最新的实验和理论进展.首先介绍了少体实验中实现的谐振子势阱中确定原子数的精确制备,亚稳态势阱和双阱系统中原子的隧穿,以及强相互作用下等效自旋链的实验结果.然后深度解析了理论研究方面,特别是基于精确可解模型的一些重要结果,包括亚稳态势阱中相互作用原子的隧穿概率,以及相应实验上常见势阱的能谱分析、密度分布、隧穿动力学以及强相互作用极限下的有效自旋链模型等. 相似文献
12.
The forces acting on interacting moving atoms exposed to resonant laser radiation are calculated. It is shown that the forces acting on the atoms include the radiation pressure forces as well as the external and internal bias forces. The dependences of the forces on the atomic spacing, polarization, and laser radiation frequency are given. It is found that the internal bias force associated with the interaction of atomic dipoles via the reemitted field may play an important role in the dynamics of dense atomic ensembles in a light field. It is shown that optical size resonances appear in the system of interacting atoms at frequencies differing substantially from transition frequencies in the spectrum of atoms. It is noted that optical size resonances as well as the Doppler frequency shift in the spectrum of interacting atoms play a significant role in the processes of laser-radiation-controlled motion of the atoms. 相似文献
13.
V. A. Kartoshkin 《Optics and Spectroscopy》2018,125(1):10-13
The interaction of spin-polarized cesium atoms with cesium and rubidium atoms under conditions of optical orientation of atoms is considered. On the basis of data on spin-exchange complex cross sections in the Cs–Cs and Cs–Rb systems, a calculation of a magnetic resonance frequency shift of cesium atoms in a Cs–Rb mixture, as well as comparison of the calculated values of the frequency shift with experimental data, is performed. 相似文献
14.
Self assembled monolayers (SAM) formed from nonanethiols on thin gold films were exposed to a beam of ground state and metastable neutral barium atoms through a nickel mask. The interaction of the Ba atoms with the nonanethiol layer, followed by an etching process, creates well defined structures on the gold film, with features below 100 nm. We compared the interaction of ground state Ba atoms and SAM molecules with respect to metastable Ba atoms, finding that by using metastable atoms the Ba dose per SAM molecule is reduced. The results indicate that nanofabrication in the nanometer range with barium atoms is feasible. PACS 07.77.Gx; 42.82.Cr; 81.16.Ta 相似文献
15.
D. Braun 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,42(1):103-108
The interaction of two–level atoms with a common heat bath leads to an effective interaction between the atoms, such that
with time the internal degrees of the atoms become correlated or even entangled. If part of the atoms remain unobserved this
creates
additional indirect decoherence for the selected atoms, on top of the direct decoherence due to the interaction with the heat
bath. I show that indirect decoherence can drastically increase and
even dominate the decoherence for sufficiently large times. I investigate indirect decoherence through thermal black body
radiation quantitatively for atoms trapped at regular positions in an optical lattice as well as for atoms at random positions
in a cold gas, and show how indirect
decoherence can be controlled or even suppressed through experimentally accessible parameters. 相似文献
16.
G. Falcone A. Gras-Marti P. Sigmund F. Smend J. Ahlert M. Schumacher P. Rullhusen L. Ziegeler 《Zeitschrift für Physik A Hadrons and Nuclei》1981,301(2):101-107
Nuclear Resonance Fluorescence spectra contain information on the slowing-down behaviour of recoiling atoms in the energy range pertinent to the specific reaction. On the basis of conventional transport theory, measured spectra for arsenic atoms with energies ?15 eV slowing down in helium are analysed. The assumption of continuous slowing down turns out to be well justified, and the thermal motion of the gas atoms is shown to influence the effective stopping power only slightly. Somewhat surprising in view of uncertainties concerning the charge state of the recoiling atoms, theoretical predictions based on Lenz-Jensen elastic interaction agree well with the measured spectra. At present, the experimental data do not allow direct inversion, but the calculated spectra are shown to depend sensitively on the stopping-power input. 相似文献
17.
An aluminum crystallite containing 500 atoms with an effective dual interaction potential computed within the framework of the theory of pseudopotential was modeled by using the method of molecular dynamics. The binding energies of complexes from impurity magnesium atoms and vacancies as well as the migration activation energies (MA) of the magnesium and aluminum atoms were computed under shear strain conditions. It is shown that shear strain results in separating out of the individual directions energetically most favorable for the formation of complexes of impurity atoms and vacancies, as well as the directions in which the MA energy values are lowered.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 49–52, December, 1990. 相似文献
18.
Analysis of Cr atom focusing deposition properties in the double half Gaussian standing wave field 下载免费PDF全文
The use of the dipole force on atoms is a new technology that is used to build nanostructures. In this way, a high quality standard nano-grating can be obtained. Based on the semi-classical model, the motion equation is investigated and the trajectories of atoms in double half Gaussian standing wave field are simulated. Compared with the Gaussian standing wave field, the double half Gaussian standing wave can well focus the Cr atoms. In order to obtain this kind of beam, a prism is designed and the experimental result shows that the beam is well generated. 相似文献
19.
I. E. Protsenko 《Journal of Experimental and Theoretical Physics》2006,103(2):167-182
A method for calculating the spontaneous emission power of several immobile dipole-interacting two-level atoms located in a volume of about the wavelength of resonance radiation has been proposed in the Schrödinger representation. It has been shown that two atoms cannot, but four atoms can, emit a superradiance pulse under the conditions corresponding to experiments with cold atoms in dipole traps. Various methods for determining the quasistationary mixed atomic states, as well as the generalization of this method to other resonance emitting systems, are discussed. 相似文献
20.
First principles study on the magnetocrystalline anisotropy of Fe--Ga magnetostrictive alloys 下载免费PDF全文
This paper investigates the electronic structure and
magnetocrystalline anisotropy of Fe--Ga magnetostrictive material by
means of the full potential-linearized augmented plane-wave method
within the generalized gradient approximation. The 3d-orbit
splitting of Fe atoms in D03, B2-like and L12 crystalline
structures of Fe--Ga is calculated with consideration of the crystal
field as well as the spin--orbit coupling effect. Because of the
frozen orbital angular momenta of the 3d-orbit for Fe atoms in Fe--Ga
magnetostrictive alloys and the spin--orbit coupling, the
distribution of the electron cloud is not isotropic, which leads to
the anisotropy of exchange interaction between the different atoms.
A method on estimating the magnetocrystalline anisotropy of Fe--Ga
alloys by means of calculating orbit-projected density of states for
Fe atoms is performed. The anisotropic distribution of the electron
cloud of Fe atoms in these three crystalline structures of Fe--Ga is
studied based on the above method showing the highest magnetic
anisotropy for B2-like structure. This qualitative method comes
closer to physical reality with a vivid physical view, which can
evaluate the anisotropy of electron cloud for 3d transition atoms
directly. The calculated results are in good agreement with both the
previous theoretical computation and the tested value on the
magnetic anisotropy constant, which confirms that the electron cloud
anisotropy of Fe atoms could well characterize the
magnetocrystalline anisotropy of Fe--Ga magnetostrictive material. 相似文献