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利用相干态表象下的Wigner算符, 重构了增光子奇偶相干态的Wigner函数.根据此Wigner函数在相空间中随复变量α的变化关系, 讨论了增光子奇偶相干态的非经典性质. 结果表明, 增光子奇偶相干态总可呈现非经典性质, 且在m取奇(或偶)数时, 增光子偶(或奇)相干态更容易出现非经典性质. 根据增光子奇偶相干态的Wigner函数的边缘分布, 阐明了此Wigner函数的物理意义. 同时, 利用中介表象理论获得了增光子奇偶相干态的量子tomogram函数.
关键词:
增光子奇偶相干态
Wigner函数
中介表象
tomogram函数 相似文献
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采用密度泛函理论中的PW91/DNP方法研究了Cun(n=2~20)团簇的稳定性和电子性质.结果表明:在n=2~8区间,平均结合能曲线几乎呈现线性增长;在n=9~20区间,平均结合能曲线相对较平缓.Cun(n=4,7,8,17)团簇相对较稳定.Cun(n=2,4,8,13,19)团簇的能隙值相对较大,化学活性较弱.在n=2~20区间,垂直电离能略微大于绝热电离能,绝热亲和能略微大于垂直亲和能.在n=2~9区间,电离能曲线呈现出显著的奇—偶振荡效应,即n为偶数团簇的电离能比临近奇数团簇的要大;亲和能曲线呈现出同电离能曲线相反的奇—偶振荡效应. 相似文献
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采用密度泛函理论中的PW91/DNP方法研究了Cun(n=2~20)团簇的稳定性和电子性质。结果表明:在n=2~8区间,平均结合能曲线几乎呈现线性增长;在n=9~20区间,平均结合能曲线相对较平缓。Cun(n=4, 7, 8, 17)团簇相对较稳定。Cun(n=2, 4, 8, 13, 19)团簇的能隙值相对较大,化学活性较弱。在n=2~20区间,垂直电离能略微大于绝热电离能, 绝热亲和能略微大于垂直亲和能。在n=2~9区间,电离能曲线呈现出显著的奇—偶振荡效应,即n为偶数团簇的电离能比临近奇数团簇的要大;亲和能曲线呈现出同电离能曲线相反的奇—偶振荡效应。 相似文献
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在相对论平均场理论框架下, 用NL-3和NL-Z两组相互作用参数研究了4个同位素链28Ni,54Xe,78Pt,94Pu的基态性质. 发现,在Hatree近似下奇A核结合能理论计算值与实验值的相对误差反而普遍比偶偶核小. 这说明用相对论平均场理论,即使不考虑矢量介子的空间分量,仍可以比较可靠地计算奇A核结合能. 相似文献
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近年来, 硅烯(单层硅)由于其独特的结构和电子性质以及在量子霍尔效应等领域的潜在应用而成为理论和实验研究的一个热点. 借助于四带次近邻紧束缚模型, 详细计算和研究了硅烯中受电场调制的体能隙和电子能级. 结果表明: 硅烯原胞中的两个子格处于不同的平面上, 可以通过外电场区分和控制这两个子格, 这将破坏在纯石墨烯中无法被破坏的K-K'对称性, 并消除由这一对称性导致的电子能级的二重简并; 外加电场还会引起硅烯中次近邻格点之间的Rashba自旋轨道耦合, 这一作用会在不同狄拉克点有选择地消除电子能级在部分电场点的简并, 相邻能级从交叉状态变为反交叉状态; 电子能级中除一些孤立的交叉点外, 每个能级都具有确定的自旋取向, 石墨烯中电子能级的四重简并在硅烯中被完全消除, 从而导致填充因子ν=0, ±1, ±2, ±3,…的量子霍尔平台. 相似文献
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In this paper we have calculated the variations of the gap Δ'(0,d) and transition temperature T'c in small metallic grains as functions of grain size (or the level spacing d between discrete electronic states) for the cases of odd and even numbers of electrons by applying the random matrix theory to the mean field theory. We find the presence of enhancement of superconductivity and critical dc, where the superconductivity of small grains breaks down. This agrees with Anderson's prediction (1959 J. Phys. Chem. Solids 11 28). We find that in the grains, as the size is lowered, the transition temperature T'c decreases and Δ'(0,d)/kBT'c≤πe-γ in odd numbers of electrons, and for Gaussian orthogonal and unitary ensembles in some regimes Δ'(0,d)/kB T'c>πe-γ in even numbers of electrons. 相似文献
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本文报道了从粒子背散射堵塞效应的实验中所发现的单晶Si的{111}晶面粒子堵塞坑的新现象。单晶Si的{111}晶面有两个面间距d(111)(a)和d(111)(b),而{110}晶面只有一个面间距d(110)。由此导致两者的堵塞坑是不同的,我们已从α粒子和质子的Si单晶堵塞效应的实验得到了证实。并由此估计了d(111)(a)和d(111)(b)以及d(110)的2ψ1/2角。据作者了解,到目前为止,国内外还没有人发现此现象。此现象的发现对复杂晶体的堵塞和沟道效应的研究开阔了前景。
关键词: 相似文献
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第Ⅰ类多模叠加态|ψ1(3)〉q中广义磁场的高次和压缩 总被引:1,自引:0,他引:1
构造了由多模相干态|{Zj} > q、多模真空态|{Oj} >q和多模相干态的相反态|{-Zj} > q三者的线性叠加所组成的第Ⅰ类三态叠加多模叠加态光场|ψ1(3) > q,利用多模压缩态理论,研究了态|ψ1(3) > q中广义磁场分量的等幂次高次和压缩效应.结果发现:态|ψ1(3) > q是一种典型的三态叠加多模非经典光场;当各模的初始相位和 满足一定的取值条件、并且态|ψ1(3)〉q中任意两态的态间初始相位差(θpq(R)-θ0q(0))、(θnq(R)-θ0q(0))和(θpq(R)-θnq(R))等分别在各自的闭区间内连续变化时,则态|ψ1(3) > q的广义磁场分量(即第一正交相位分量)总可分别呈现出周期性变化的、等幂次的奇数模-偶数次、偶数模-奇数次、偶数模-偶数次或者奇数模-奇数次的高次和压缩效应. 相似文献
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增加光子奇偶q相干态的高阶压缩效应 总被引:8,自引:3,他引:5
通过数值计算研究了增加光子奇q相干态aq+m|α>qo和增加光子偶q相干态aq+m|α>qe的高阶压缩效应.结果表明:当q较小时,态aq+m|α>qo和aq+m|α>qe都能呈现出强烈的奇次方阶压缩效应,但无偶次方阶压缩效应,而且奇次方阶压缩随m的增大而增强.当m=0时aq+m|α>qo和aq+m|α>qe为光场振幅偶次幂的最小测不准态,但当m≠0时它们不是光场振幅偶次幂的最小测不准态. 相似文献
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ZHENG Renrong CHEN Zhiqian & ZHU Shunquan . Department of Physics Shanghai Normal University Shanghai China . Department of Physics Southwest Normal University Chongqing China . Department of Computer Electric Technology Shanghai Business School Shanghai China 《中国科学G辑(英文版)》2005,48(4):431-441
1 IntroductionThe superconductivity of small metallic grains has been attracting a lot of attentions. On one hand, Anderson[1] predicted that the superconductivity would disappear if a me- tallic grain was so small that the spaces between the nearest neighbor energy levels in the system became larger than the energy gap of the bulk metallic superconductor; On the other hand, it was found in experiments made in the 1960s[2] that the critical tem- perature of superconductivity of small metallic … 相似文献
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A theory of bandwidth anisotropy in metallic ferromagnets developed previously is specialised to the case of 5d electrons in a hexagonal close-packed lattice. This theory is combined with a model for 5d electrons in the heavy rare earth metals to give a new theory for the low temperature values of the magnetic anisotropy coefficientsκ 2 0 andκ 4 0 in Tb, Dy, Ho, Er and Tm. In this theory the magnetic anisotropy is due to a combination of (i) crystal fields acting on 5d and 4f electrons and (ii) bandwidth anisotropy associated with a dependence of 5d bandwidths on magnetization direction. After use is made of empirical upper limits on the eighth order magnetic anisotropy in Gd, there remain four partially adjustable parameters of importance in the theory. These can be chosen to give a good fit to the six observed values forκ 2 0 andκ 4 0 in Tb, Dy and Ho. Crystal fields corresponding to negative point charges are seen by 5d electrons, but because of 4f – 5d interactions effective fields of larger magnitude and opposite sign act on 4f shells. Bandwidth anisotropy gives a significant contribution toκ 4 0 of opposite sign to that due to crystal fields, and dominates the latter in Tb and Er. 相似文献
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R. Bruce King 《Molecular physics》2013,111(12):1855-1860
The icosahedral symmetry I?≈?A 5 of the atomic d shell can arise from the symmetries of the five-dimensional d orbital space through the subgroup chain SO(5)???SO(3)???I or O(5)???S 6???S 5???I. In the latter case the symmetric group S 5 can be generated from I?≈?A 5 by addition of the period 4 kaleidoscope operator K, which mixes the d orbitals with m?=?±1 and those with m?=?±2. Furthermore, separation of the d n configurations into two sets according to the parity of n (even or odd) and the irreps of SO(5) is found to lead to new relationships between the multiplicities and seniorities of the corresponding terms. Thus the sums of the seniorities and multiplicities for even and odd n for a given irrep of SO(5) lead to a constant, namely 12. Furthermore, new pseudodegeneracies are found to arise when the energy expressions of pairs of otherwise equivalent terms with different seniorities for a given d n are adjusted to remove the radicals arising from solution of the quadratic secular equation. In addition to the well-known 2H/2P degeneracy for d3, 3F/3P degeneracies are found for d4 and a 2D/2S pseudodegeneracy is found for d5. 相似文献
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W. Zhang S. You C. Sun Y. Zhang J. Xu Z. Ma Y. Feng H. Liu P. Quinet é. Biémont Z. Dai 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(1):1-8
First laser spectroscopic measurements of the 6s5d3D1-6s6p1P1 and 6s5d3D2-6s6p1P1 transitions in several isotopes of atomic barium have been performed. The hyperfine structure of these transitions was optically
resolved and isotope shifts for even and odd isotopes were determined. The isotope shifts show a deviation from their expected
behavior for odd isotopes in an analysis based on King-plots. This observation puts atomic structure calculations at test
because available theories do not predict this. A profound understanding of the wavefunctions for heavy alkaline earth systems
like barium (Ba) and radium (Ra) is essential for a theoretical evaluation of their sensitivity to fundamental symmetry breaking
effects such as they could be observed, e.g., through permanent electric dipole moments. Further the absolute frequency of
the 6s2
1S0-6s6p3P1 intercombination line in 138Ba was determined to be 12 636.6232(1) cm-1. 相似文献
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Z. A. Samoilenko V. D. Okunev T. A. D’yachenko E. I. Pushenko S. J. Lewandowski P. Gierlowski A. Klimov A. A. Abal’oshev 《Technical Physics》2004,49(5):572-576
A linear relationship between the critical temperatures Tmax and Tmin in the temperature dependences of the resistance of La0.6Sr0.2Mn1.2O3 single-crystal films that have a mesoscopic irregularity (metallic clusters in an insulating matrix) is found. A correlation between the atomic order and electronic structure of the films is studied by taking X-ray diffraction patterns and optical absorption spectra. It is shown that a rise in Tmax and a simultaneous decrease in Tmin cause correlated local changes in cluster areas of the structure. Namely, the volume occupied by a family of Mn-O planes with large interplanar spacings (d=2.04–2.08 Å) shrinks, while the volume occupied by a family of closer spaced (d=1.90–1.99 Å) planes grows. In the electronic subsystem, the density of states at ?ω=1.5 and 2.4 eV, which are due to Mn3+ and Mn4+ ions, increases, and the contribution from Mn2+ states at ?ω=0.9 eV decreases. As the charge states associated with Mn3+ and Mn4+ ions become dominant, the Mn-O binding energy grows. As a result, the contribution of the structural states with smaller d increases, thereby raising the density of states in the electronic subsystem at energies between 0.5 and 2.7 eV. The effect of self-organization in the multicomponent LaSrMnO system shows up in the transition from the heavily distorted rhombohedral to the less distorted orthorhombic structure. 相似文献
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Horst Stöcker Walter Greiner Werner Scheid 《Zeitschrift für Physik A Hadrons and Nuclei》1978,287(1):121-122
Recent experimental results for 81 196 Tl115 along with that of 81 198 Tl115 are analysed. It is shown that staggering observed in the excitation energy of the even and odd spin states in these odd-odd mass transitional nuclei is due to the residual interaction between the two odd particles. 相似文献