互相垂直的均匀磁场和电场中一维带电谐振子的双波描述

研究互相垂直的均匀磁场和电场中一维带电谐振子的量子单波及量子双波的描述     

有旋电子在电磁场及二维谐振子场中运动的双波描述

研究有旋非相对论性电子在相互垂直的均匀电磁场及二维谐振子场中运动的量子单波及量子双波描述. 关键词： 双波描述 有旋电子 电磁场 谐振子场     

均匀外电场中带电谐振子运动的双波函数描述

用双波函数量子理论描述电谐振子在均匀外电场中的运动，得到对单个带电谐振子运动状况的完全描述。通常量子力学中的期望值公式为双波函数对某一类系综的平均结果。     

频率含时谐振子运动的双波描述

应用双波函数定义频率含量谐振子的量子状态,频率含时谐振子的运动得到更完整的描述,双波描述的经典极限与经典力学结果相一致。     

基于Morse势能函数谐振子模型的声传播研究

对于复杂的体系,组成体系的各粒子间的相互作用决定其能量状态。对于不同势场,描述粒子运动规律的Schrodinger方程是不同的微分方程。本文在原来的Hamilton谐振子数学模型基础上,通过引入Morse势能函数代替原来的简谐振子势模型,研究了一维气体分子链中声传播的问题。从能量的概念出发,将声传播问题转换成求解谐振子的波函数以及能量本征值的问题,建立配分函数与热力学量之间的关系,以Morse势能函数的振子模型构造的声传播模型求取声压及声能量。通过比较,经典方法与量子谐振子模型计算的一维声压吻合。     

谐振子的经典和量子统计分布

经典统计与量子统计之间存在着一定的区别和联系,并在一定的条件下可以相互转换.本文以物理学中非常重要的谐振子模型为例,分别从谐振子的运动状态描述、能量、测不准原理、运动空间分布、概率分布等方面对这两种统计方法进行了比较从而归纳出谐振子的经典统计与量子统计分布的异同,加深了对量子动力学行为的进一步理解和认知.     

各向同性带电谐振子在均匀磁场中的能谱壳结构

推导出了二维、三维各向同性带电谐振子在均匀磁场中的能级表达式,并利用Mathematica软件进行编程、图解,讨论其壳结构.     

质量含时谐振子运动的双波描述

应用双波理论描述质量含量谐振子的量子运动,得到了振子各相关物理量的时间演化方程以及双波描述的经典极限与纯经典力学结果一致的结论。     

准恒场驱动谐振子的物理特性

研究了准恒场驱动谐振子的物理特必。结果表明，以经典方式描述了驱劝光场的位相发生绝热时，在输出光场中会出现几何位相。考虑了位相变化或不变时输出光场的量子态的演化。发现输出场的光子数振荡么及演化的周期行为。     

一个描写谐振动的态──相干态

在量子力学中,谐振子常用能量本征态描述其所处的状态。但是,能量本征态只反映了谐振动一个方面的特征,即能量或振幅,而对振动的位相特征却没有涉及。如果有两个谐振子,它们在经典描写下有相同的频率和振幅,但有不同的初位相,那么在量子力学中,这两个振子的运动状态怎样区别呢? 显然,只用能量本征态是不能反映运动状态的全部特征的。而在量子力学中讨论谐振子、光场等状态时,如果用相干态来描述,不但有比较直观的经典类比,而且在很多问题里也使计算更为简化。1.谐振子的能量本征态; 由谐振子的哈密顿求解能量算符的本征方程,得到本征值和本…     

EXACT SOLUTIONS OF CLASSICAL SCALAR FIELD EQUATIONS

We give a class of exact solutions of quartic scalar field theories. These solutions prove to be interesting as are characterized by the production of mass contributions arising from the nonlinear terms while maintaining a wave-like behavior. So, a quartic massless equation has a nonlinear wave solution with a dispersion relation of a massive wave and a quartic scalar theory gets its mass term renormalized in the dispersion relation through a term depending on the coupling and an integration constant. When spontaneous breaking of symmetry is considered, such wave-like solutions show how a mass term with the wrong sign and the nonlinearity give rise to a proper dispersion relation. These latter solutions do not change the sign maintaining the property of the selected value of the equilibrium state. Then, we use these solutions to obtain a quantum field theory for the case of a quartic massless field. We get the propagator from a first-order correction showing that is consistent in the limit of a very large coupling. The spectrum of a massless quartic scalar field theory is then provided. From this we can conclude that, for an infinite countable number of exact classical solutions, there exist an infinite number of equivalent quantum field theories that are trivial in the limit of the coupling going to infinity.     

PHOTOIONIZATION IN AN INTENSE LASER FIELD

In this paper classical approaches are used to study the detailed processes of photoion-ization in an intense laser field. The analytic expression of the ionization rate is derived. Finally, the results obtained are compared with existing theories such as Landau's tunnel theory and Keldysh-Faisal-Reiss theory.     

Classical and quantum conformal field theory

We define chiral vertex operators and duality matrices and review the fundamental identities they satisfy. In order to understand the meaning of these equations, and therefore of conformal field theory, we define the classical limit of a conformal field theory as a limit in which the conformal weights of all primary fields vanish. The classical limit of the equations for the duality matrices in rational field theory together with some results of category theory, suggest that (quantum) conformal field theory should be regarded as a generalization of group theory.On leave of absence from the Department of Physics, Weizmann Institute of Science, Rehovot 76100, Israel     

Dirac方程中的量子与经典对应

根据Heisenberg对应原理(HCP),在经典极限下厄密算符的量子矩阵元对应经典物理量的Fourier展开系数.将HCP应用到相对论领域的Dirac方程中,对于自由粒子和在匀磁场中的带电粒子,其量子算符的矩阵元在经典极限下对应着相对论物理方程的解.计算表明,在经典极限下量子期望值就是对应经典物理量的时间平均值.     

The classical field limit of scattering theory for non-relativistic many-boson systems. I

We study the classical field limit of non-relativistic many-boson theories in space dimensionn≧3. When ?→0, the correlation functions, which are the averages of products of bounded functions of field operators at different times taken in suitable states, converge to the corresponding functions of the appropriate solutions of the classical field equation, and the quantum fluctuations are described by the equation obtained by linearizing the field equation around the classical solution. These properties were proved by Hepp [6] for suitably regular potentials and in finite time intervals. Using a general theory of existence of global solutions and a general scattering theory for the classical equation, we extend these results in two directions: (1) we consider more singular potentials, (2) more important, we prove that for dispersive classical solutions, the ?→0 limit is uniform in time in an appropriate representation of the field operators. As a consequence we obtain the convergence of suitable matrix elements of the wave operators and, if asymptotic completeness holds, of theS-matrix.     

GUIDING OF PLASMA BY ELECTRIC FIELD AND MAGNETIC FIELD

The relationship between the transported ion current and the cathodic arc current is determined in a vacuum arc plasma source equipped with a curved magnetic filter. Our results suggest that the outer and inner walls of the duct interact with the plasma independently. The duct magnetic field is a critical factor of the plasma output. The duct transport efficiency is to maximize at a value of bias plate voltage in the range +10 V to +20 V, and independent (within our limit of measurement) of the magnetic field strength in the duct. The plasma flux is composed of two components: a diffusion flux in the transverse direction due to particle collisions, and a drift flux due to the ion inertia. The inner wall of the magnetic duct sees only the diffusion flux while the outer wall receives both fluxes. Thus, applying a positive potential to the outer duct wall can reflect the ions and increase the output current. Our experimental data also show that biasing both sides of the duct is more effective than biasing the outer wall alone.     

磁AB效应及其理论解释

本文介绍磁AB效应及其两种理论解释 ,进而说明经典电动力学具有局限性 ,量子力学是更高层次的物理理论     

磁场中的超导膜

本文将文献[1]的理论推广到较厚的超导膜。首先采用能隙是常数的模型,借助于Schrief-fer方法,导出磁场中超导膜的补偿方程和电流方程。利用所得的方程,研究了均匀外磁场对金属膜超导性质的影响,讨论了超导膜在磁场中的相变,给出了确定超导膜的能隙、磁矩、平衡临界场H_c,以及分别相应于过冷和过热区域边界的临界场H_(c1)和H_(c2)的一般公式。所有这些表达式,在局域极限下,化为Гинзбург-Ландау理论的相应结果;在薄膜情形下,回到文献[1]的结果,文中对一般情形下的非局域效应作了具体的讨论。     

原子在强磁场中的能谱特征

本文使用一种微扰法计算强磁场中的Na原子(m=-2,z宇称π₂=+)在强场混合区的能级位置和振子强度。理论能谱的一些特征可以较好地描述一些实验能谱的特征。对得到的能谱所做的傅里叶变换分析表明,除了传统的准朗道共振外(在零场电离阈附近间距近似为1.5?ω_c,ω_c为电子迴旋频率),还存在有一系列大小与磁场强度无关的“共振”间距,与其他理论所给出的相一致,还从所用微扰法中的零级能量公式出发,对这些间距给予量子力学解释。 关键词：