低频强场作用下三维光子晶体中二能级原子的自发辐射性质

研究了处于三维光子晶体中,且在强相干的低频场的驱动下的单个二能级原子的自发辐射性质.由于低频场的影响,使得原子产生了在跃迁过程中吸收或发射一个低频光子的衰减渠道.这些跃迁导致了自发辐射的量子干涉,再加上光子晶体能带带边的作用,自发辐射被显著抑制.原子的布居俘获依赖于原子上能级与能带带边的相对位置,低频场的频率和原子不同跃迁通道间的相对跃迁强度.关键词：光子晶体二能级原子自发辐射     

基于偏振纠缠光子对的单光子源

提出了一种基于参量下转换纠缠光子对获得单光子源的实验方案,并对实验的光路、数据采集方面做了详细介绍.实验结果显示,由此方案获得的单光子源的品质要优于弱相干光式的单光子源两个数量级,即多光子光脉冲出现的概率降低了100倍.实验结果表明此方案有望得到实际应用.关键词：单光子源参量下转换反符合测量     

读出效率对光与原子纠缠产生的影响

在光与原子纠缠态产生中,自旋波读出效率是影响纠缠质量的一个重要因素.本文在实验和理论上研究了读出效率与纠缠质量(Bell参量)的关系.实验上利用~(87)Rb冷原子系综中的自发Raman散射过程产生了光与原子量子纠缠.通过改变读光功率或OD (光学厚度),实现了读出效率的变化.在此基础上,研究了光与原子纠缠质量(Bell参量)随读出效率变化的关系.该实验将为高保真度的光与原子纠缠产生提供帮助.     

Planar-homeotropic transition observed for B2 phase of banana-shaped thioester

1,3-Phenylene bis{4-[(4-dodecyloxybenzoyl) sulfanyl] benzoate} (12OSOR) possessing banana-like achiral molecules has been studied by complementary methods to investigate linear dielectric as well as antiferroelectric properties of its B₂ phase. To this end, the following experimental methods were used: differential scanning calorimetry, polarizing microscopy, dielectric spectroscopy and reversal current method. As found, 12OSOR compound with bent-core molecules exhibits only B₂ phase that happens to be antiferroelectric. Dielectric spectra have been measured using the dielectric spectrometer based on Agilent 4294A impedance analyzer. The measurements have been done using HG 5 µm cells (giving homogeneous orientation) with gold electrodes. Thermal, dielectric, and electro-optic properties of 12OSOR are discussed.     

Comparative analysis of real and \mathcal{P}\mathcal{T}-symmetric Scarf potentials

The Scarf I and Scarf II potentials are discussed within a common mathematical framework, which is then specified to handle the two potentials separately both in the conventional Hermitian and in the -symmetric setting. The physically admissible solutions are identified in each case together with the corresponding energy eigenvalues. Several main differences between the -symmetric Scarf I and II potentials are pointed out. These include the presence and absence of the quasi-parity quantum number, the sign of the pseudo-norm, the mechanism of the spontaneous breakdown of symmetry and the non- orthogonality of otherwise admissible solutions in the Scarf I potential. Similarities and differences with respect to the corresponding Hermitian systems are also pointed out.     

Judd—Ofelt theory: past,present and future

The original Judd-Ofelt theory is briefly presented in the terms of effective operators defined in the traditional form that has been used for many years for the interpretation of the f spectra of rare earths. The semi-empirical approach of the Judd-Ofelt theory that defines the one-particle parametrization scheme is modified here. The unit tensor operators that act within the orbital space are replaced by double tensor operators acting within the spin-orbital space. This extension enables one to include the impact of the relativistic effects upon the transition amplitude. At the same time it leads to a generalization of the theoretical approach to f ? f transitions, especially in the case of those that are not described by the standard scheme.     

Experiment Researches on Active Fibre Probe for Scanning Near-field Optical Microscopy

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电子束泵浦注入锁定XeCl准分子激光理论模拟

模拟了强流电子束泵浦下,激光腔内的反应动力学过程,及不同注入时间、不同注入强度下注入锁定的激光生成、放大和输运过程。对实际非稳腔使用了一维伸展近似,并采用了预估—校正方法对光子输运方程进行求解。模拟结果表明,激光生成阶段,注入种子光源后,激光输出质量明显改善,使自发辐射部分受到了明显的抑制。得到了在不同注入强度、注入时间以及放大倍数下的激光输出的光谱特性,能量及各种效率的关系。发现锁定效果最佳时的注入时间出现在小信号增益峰值处。     

Two Higgs bi-doublet left-right model with spontaneous P and CP violation

A left-right symmetric model with two Higgs bi-doublet is shown to be a consistent model for both spontaneous P and CP violation. The flavor changing neutral currents can be suppressed by the mechanism of approximate global U(1) family symmetry. The constraints from neural K meson mass difference Δm _K are calculated and it is demonstrated that a right-handed gauge boson W ₂ contribution in box-diagrams with mass well below 1 TeV is allowed due to a cancelation caused by a light-charged Higgs boson with a mass range of 150–300 GeV. The W ₂ contribution to ε _K can be suppressed from an appropriate choice of additional CP phases appearing in the right-handed Cabbibo-Kobayashi-Maskawa matrix. The model is also found to be fully consistent with B ⁰ mass difference Δm _B and the mixing induced CP violation sin2β _{J/ Ψ}, which is usually difficult for the model with only one Higgs bi-doublet. The new physics beyond the standard model can be directly searched at the colliders LHC and ILC. Supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 10475105 and 10491306) and the Key Project of Chinese Academy of Sciences (CAS)