激光驻波场作用下原子束横向速度聚束

分别从理论和实验上研究了在负失谐强激光驻波场作用下，原子速度聚集在某一特定速度附近的现象，即速度聚束，产生速度聚束的原因是，当原子的速度小于某一临界速度时，激光对原子的辐射压力加热原子，而当原子速度大于这个临界速度时则冷却原子，因此原子将伙集于这个临界速度附近。     

厚透镜近似下激光驻波场中原子动力学研究

研究了在厚透镜近似下 ,原子在激光驻波场中的动力学行为 .通过直接演化一维薛定谔方程 ,发现当激光的强度较大时 ,原子束将会聚焦形成几个焦点 .如果激光的强度更大 ,驻波场中的原子将会出现一种“隧道”现象 ,此时 ,原子受一些实验参数 (如焦平面位置、激光强度等 )的影响程度将大大降低 .这种现象有利于提高原子在驻波场中聚焦沉积的效果 . The dynamics of atoms in laser standing wave (SW) in the regime of over-focused immersion-lens is studied. Through directly evolving a one-dimensional Schrdinger equation, we find that multiple focusing appears when laser intensity is larger than that required for simple focusing. If laser intensity is much higher than that for the single focusing, a "channeling" phenomenon appears, which is insensitive to the variation of some parameters, such as focal plane position and laser intensity...     

驻波场中两能级原子运动方程及其解

首次将固体量论中的ＬＬＰ变换用于处理两能级原子与驻波场相互作用体系的全量子哈密顿量。这一结果对于研究原子束穿透驻波场所造成的折射十分重要。     

Analysis of Nanometer Structure for Chromium Atoms in Gauss Standing Laser Wave

The equation of motion of two-level chromium atoms in Gauss standing laser wave is discussed and the distribution of chromium atoms is given under different transverse velocity conditions. The results show that the focusing position of atoms will be affected by the transverse velocity of atoms. Based on the four-order Runge- Kutta method, the locus of chromium atoms in Gauss standing laser wave is simulated. The three-dimensional characteristics of nanometer structures are stimulated under perfect and emanative conditions.     

高斯激光驻波场沉积Na原子的量子理论分析

利用量子理论,通过CRANK-NICOLSON数值方法对23Na原子受激光驻波场作用的物理过程进行模拟.模拟结果表明:正失谐时,原子以λ/2为周期会聚在驻波光场中波节处.随着光势阱加深或原子纵向速度改变,原子会聚结果分别符合薄透镜、厚透镜及沟道化模型.厚透镜模型中,当原子纵向速度增加,原子密度峰位置沿z方向向后漂移,峰在z方向半高宽增加.当激光功率增加或激光束腰减小,会聚面上峰半高宽减小,对比度增加,峰值增加.     

Optical Pumping of Samarium Atoms in a Bichromatic Laser Field in the Presence of Velocity-Changing Collisions

Dark resonances in the ¹⁵⁴Sm -system 4f ⁶6s ²(⁷ F ₀) 4f ⁶6s6p(⁹ F ₁ ⁰) 4f ⁶ s ²(⁷ F ₁) are observed alongside the velocity selective optical pumping. The shape of the resulting spectra strongly depended on the buffer gas (He, Ar) pressure due to velocity-changing collisions (VCC): the sign of the effect could be reversed from the dark to the bright resonance. The observed spectra are interpreted within the framework of the hard-sphere collision model. The role of VCC in the formation of the dark state in the -system is discussed.     

原子的波动性

激光冷却所达到的低温明确地显示出量子力学最使人着迷的结论之一:原子和其他一些实物粒子的波动性,这是路易·德布罗意早在1924年就预言了的①.越冷的粒子,越能显示出它们的波动性.近年来,两个新的很活跃的领域显示出与光的波动光学同样的效应:原子光学和原子干涉度量学.     

Strong Standing Gravitational Wave in a Closed Universe

We consider homogeneous time-like sections of a spacetime that correspond to Bianchi type-VIII model. For this model, we find a new class of regular solutions of vacuum Einstein’s equations, which describe a strong standing gravitational wave in a Universe, which is closed in some direction.     

Two-Level Atom in a Standing, Electromagnetic Wave

We study a two-level atom interacting with a standing electromagnetic wave, and work out the wave functions, the energy values and the momentum values of the atom.     

Specific Features of the Kinetics of Generation of an Annihilation Gamma-Ray Laser

Russian Physics Journal -     

双色驻波场中梯形三能级原子所受整流偶极力的涨落分析

本文基于文献[1]利用双色驻波场作用于三能级原子获得宏观数量个光学波长上符号保持不变的整流偶极力的工作基础上,运用量子回归定理计算了所得整流偶极力在一个光学波长上的涨落.结果表明:原子偶极零点振动与光场幅度梯度相互作用引起的偶极力的涨落D1的值较大,是整流偶极力涨落的主要因素,且其随空间的变化规律与整流偶极力相似;原子偶极与真空零点振动相互作用导致偶极力的涨落Ds较小,几乎可以忽略不计.由于力的起伏所导致的加热效应不利于中性原子的偶极束缚[6].     

Motion of Cold Atoms in a Labyrinth Created by a Three-Dimensional Optical Lattice

Journal of Russian Laser Research - The coherent dynamics of a cold two-level atom in a three-dimensional optical lattice is treated in the semiclassical approximation, taking into account the...     

驻波场中相位迟后的偶极力

计算了二能级原子在一个驻波场中的辐射压力，给出了在不对空间平均时的辐射压力的普遍表达式，指出辐射压力的零级项应应于受激压力，而一级项对应于偶极力，高队项则可忽略。文中详细地计算了各种不同情况下的偶极力和相位，指出对于不同速度，相位有不同的迟后，这样的结果将严重地影响原子在驻波场中的动力学，用光子再分配模型简单地对有力的相位随速度的变化作了解释。     

Stochastic Behavior of Particles in a Circularly Polarized Standing Wave

The particle motion in a standing left circularly polarized wave is studied. For wave frequency lower than the ion cyclotron frequency ?ci, the slow varying trajectory is given by the ponderomotive force FNL=q2?|E|2/[m?(?-?ci)]. However, for ? close to ?ci, stochastic trajectories occur. These stochastic trajectories are due to the overlapping of closed orbits due to each of the propagating waves which form the standing wave.     

弦线上驻波的研究

讨论了弦振动横波波动方程,研究了固定线密度时弦振动的张力与波长、张力与频率之间的关系,利用origin软件得出实验曲线,并找出研究张力和波长曲线关系时的最佳频率及研究张力和频率曲线关系时的最佳波长.     

Specific Features of Nonlinear Spin Wave Localization in a Layered Ferromagnet under the Action of the Magnetic Anisotropy of Layers

Physics of the Solid State - A trilayer structure model has been investigated, in which uniaxial ferromagnetic layers and thin-film interfaces between them are characterized by the magnetic...     

Standing Waves along a Microwave Generated Surface Wave Plasma

Two surface wave plasma columns, generated by microwave power in argon at gas pressures of 0.05 torr to 330 torr, interact in the same discharge tube to form standing surface waves. Radial electric field Er and azimuthal magnetic field H? outside the discharge tube are measured to be 90° out of phase with respect to axial position and to decay exponentially with radial distance from the tube axis. Maximum light emission occurs at the position of maximum H?, and minimum Er. Electron temperature and density are measured at low pressures with double probes inserted into the plasma at a null of Er. Measured electron densities compare well with those predicted by Gould-Trivelpiece (GT) surface wave theory. Measured electron temperatures are the same order of magnitude as temperatures predicted by positive column theory.     

Kinetics of Atomic Cascade in Light Exotic Atoms

The magnetic hyperfine field B _hf for Cd in the Heusler alloy Pd₂MnSn at the site of chemically introduced Ag has been investigated by PAC following the ^– decay of ¹¹¹Ag. Sign and temperature dependence of B _hf have been determined. Comparison of the result B _hf(T=0)=+8.0(1) T with earlier data and ab-initio band structure calculations leads to the conclusion that the Ag activity has been incorporated at the Mn site.     

Photo-Ionization of Hydrogen Atom in a Circularly Polarized Standing Electromagnetic Wave

Applying time-independent non-perturbative formalism to the photo-ionization of hydrogen atom immersed in a strong circularly polarized standing electromagnetic wave, we calculate the shift of energy levels and the distortion of wave functions for the hydrogen atom, the ionization cross section induced by the standing wave, and the angular distribution of photoelectrons and obtain some interesting results.     

驻波教学中的初相问题

从推导驻波方程的一般形式出发,讨论了入射波和反射波的初相在驻波形成中的作用和关系.