极化子效应对ZnS/CdSe量子点三阶极化率的影响

在有效质量近似下,利用量子力学的密度矩阵理论,采用无限深势阱模型,从理论上计算了考虑极化子效应后在导带子带间跃迁时ZnS/CdSe柱型核壳结构量子点二次电光效应(QEOE)和电吸收过程(EA)的三阶极化率。通过数值计算,分析了电子-LO声子和电子-IO声子相互作用对ZnS/CdSe柱型核壳结构量子点二次电光效应和电吸收过程的三阶极化率的影响。结果表明,极化子效应对二次电光效应的三阶极化率χ⁽³⁾_QEDE和电吸收过程的三阶极化率χ⁽³⁾_EA都有很大影响,并且影响的大小与量子点的尺寸大小有关。     

正方点阵上Fibonacci超元胞声子晶体的带结构

用平面波展开方法研究了水柱体作为填充物, 按照二维Fibonacci排列成超元胞填充在Hg基体中构成的声子晶体的声频带结构. 结果发现, 随着超元胞中准晶格常数的变化, 各个能带均出现三分裂. 对声场分布的研究发现了居间态的存在. 这些现象体现了准周期结构的特征. 关键词： Fibonacci排列 声子晶体 能带结构     

1925年1月：泡利宣布了不相容原理

1925年对于量子物理学来说是很重要的一年,这一年从泡利（Wolfgang Pauli）在1月宣布了不相容原理开始。这个著名的原理说明了两个完全相同的费米子不可能处在相同的量子状态,首次提供了元素周期表结构的理论基础。     

退火时间对MgB_2超导薄膜的影响

在多晶A l2O3衬底上,以B2H6作为硼源,化学气相沉积先驱B薄膜,采用Mg扩散方法,在不同退火时间条件下制备了MgB2超导薄膜。通过电阻-温度曲线测量、X射线衍射分析和扫描电子显微镜形貌观测方法,研究了退火时间对MgB2薄膜的超导特性、晶体结构、表面形貌的影响。     

拼接子镜系统计算机辅助装调研究

为了提高拼接子镜系统的装调精确度,研究了拼接子镜系统的计算机辅助装调技术,分析了拼接子镜系统的计算机辅助装调模型,采用反向优化法编写程序求解系统失调量.以37项泽尼克系数作为评价函数.当粗调误差在0.7°以内时,完全可以精确求解失调量.结果表明,求解结果准确度高,符合实际装调要求.     

Unconventional Landau Levels of Ultracold Fermionic Atoms on Two-Dimensional Honeycomb Lattice

We investigate the unconventional Landau levels of ultracold fermionic atoms on the two-dimensional honeycomb optical lattice subjected to an effective magnetic field, which is created with optical means. In the presence of the effective magnetic field, the energy spectrum of the unconventional Landau levels is calculated. Furthermore, we propose to detect the unconventional Landau levels with Bragg scattering techniques.     

Probing Quark Loop Effects on Dressed Gluon Propagator

We study the quark loop effects on the dressed gluon propagator and also on the quark propagator itself. We find that the gluon propagators are different in two phases. The quark mass effects on the gluon propagator are small but not negligible. We also study the current quark mass dependence on the bag constant.     

Lorentz violation constrained by triplicity of lepton families and neutrino oscillations

In this paper we postulate an algebraic model to relate the triplet characteristic of lepton families to Lorentz violation. Inspired by the two-to-one mapping between the group SL（2, C） and the Lorentz group via the Pauli grading （the elements of SL（2, C） expressed by direct sum of unit matrix and generators of SU（2） group）, we grade the SL（3,C） group with the generators of SU（3）, i. e. the Gell-Mann matrices, then express the SU（3） group in terms of three SU（2） subgroups, each of which stands for a lepton species and is mapped into the proper Lorentz group as in the case of the group SL（2,C）. If the mapping from group SL（3,C） to the Lorentz group is constructed by choosing one SU（2） subgroup as basis, then the other two subgroups display their impact only by one more additional generator to that of the original Lorentz group. Applying the mapping result to the Dirac equation, it is found that only when the kinetic vertex -γμθ^μ is extended to encompass γ5γμθ^μ can the Dirac-equation-form be conserved. The generalized vertex is useful in producing neutrino oscillations and mass differences.     

Photoproduction of the $\Theta^+$ and its vector and axial-vector structure

We present recent investigations on the vector and axial-vector transitions of the baryon antidecuplet within the framework of the self-consistent SU（3） chiral quark-soliton model, taking into account the 1/No rotational and linear mscorrections. The main contribution to the electric-like transition form factor comes from the wave-function corrections. This is a consequence of the generalized Ademollo-Gatto theorem. It is also found that in general the leading-order contributions are almost canceled by the rotational 1/No corrections. The results are summarized as follows： the vector and tensor K＇NO coupling constants, gK＊N= 0.74--0.87 and fk＊N =0.53--1.16, respectively, and F→KN = 0.71 MeV, based on the result of the KN coupling constant gKne =0.83. We also show the differential cross sections and beam asymmetries, based on the present results. We also discuss the connection of present results with the original work by Diakonov, Petrov, and Polyakov.     

Towards the decays of Nx（1625） the molecular picture

In this talk, we firstly overview the experimental status of Nx（1625）, which is an enhancement structure observed in K-3. invariant mass spectrum of J/ψ → pK-∧. process. Then we present the result of the decay of Nx（1625） under the two molecular assumptions, i.e. S-wave∧K- and S-wave ∑0K- molecular states. Several experimental suggestions for Nx （1625） are proposed.