NeICl体系振动预解离的含时黄金规则近似处理

在相互作用绘景中运用含时黄金规则波包近似方法，对ＮｅＩＣｌ体系的振动预解离进行计算。这里的波包传播法消除了全量子方法中需要长的传播时间的困难，又由于采用了相互作用绘景，可以选取大的时间传播步长，只需很少的传播步数即可得到解高寿命及终产物的转动态分布。     

非旋波近似下二能级原子与单模腔场相互作用过程中原子占居几率的动力学性质

采用相互作用绘景,用完全量子化方法研究了两个耦合二级能原子与单模腔场相互作用过程中,原子能级占居几率的量子动力学性质,讨论了原子间耦合系数g,平均光子数n与激发场频率ω对上述性质的影响,揭示了原子耦合与原子-场相互作用之间的联系.     

对NeCl2体系的振动预解离的含时计算

采用相互作用绘景中的含时波包传播黄金规则近似方法，对ＮｅＣｌ２体系的振动预解离进行计算，由于在相互作用绘景中波包传播采用了大的传播步长，所以只需要很少的传播步骤就可以得到产物的转动态分布，大大缩短了计算量，对ＮｅＣｌ２体系的振动预解离寿命及部分衰减宽度（产物分布）进行计算，并把结果同实验及其它计算结果进行分析比较，这种含时（ＴＤ）方法所得计算结果比不含时方法（ＴＩ）与实验符合得更好。     

两模微波激射器中三能级原子布居数随时间的演化

在相互作用绘景中,得到了两模微波激射器的腔模与注入其内的Λ型三能级原子构成的相互作用系统的演化算符的矩阵表示,以及该系统的态函数随时间的演化关系,在此基础上导出了原子布居数随时间的演化关系,由此可进一步研究布居数的振荡、反转和捕获等问题.     

两模微腔中四能级原子粒子布居数随时间的演化

在相互作用绘景中利用微扰法求解了两模微腔的腔模与注入其内的四能级原子^40Ca构成的相互作用系统的态函数随时间的演化关系,在此基础上导出了原子的约化密度算符及其粒子布居数随时间的演化关系,由此可进一步研究四能级原子在腔场中的动力学行为。     

耦合双原子与单模压缩相干态光场的相互作用

利用全量子理论,在相互作用绘景中研究了两个耦合二能级原子与单模压缩相干态光场相互作用系统粒子布居几率的时间演化规律;分别讨论了光场的相干振幅分量模平方｜α｜２、光场的压缩因子γ、原子间的耦合系数g和原子-场的耦合系数λ对系统粒子布居几率的影响.     

多能级原子与多模光场的相互作用机理研究

研究了多能级原子与多模光场的相互作用.探讨了旋波近似下N能级原子与(N-1)模光场相互作用演化规律，给出了相互作用绘景中其相应的Schrdinger方程的解析通式，分析了三能级原子、四能级原子分别与双模、三模光场相互作用的演化规律.研究结果表明：当原子初始时刻处于基态时，三能级原子与四能级原子的基态概率幅具有相同的变化规律. 关键词： 多能级原子 多模光场 旋波近似     

q-奇相干场与级联型三能级原子相互作用中场的反聚束效应

提出了q-奇相干场与级联型三能级原子相互作用的非线性理论,求得了在相互作用绘景中薛定谔方程的形式解及其在其态下的期望值。利用数值计算讨论了q形变对相互作用中场的反聚束效应的影响。经研究发现,q形变对反聚束效应的调制能力很强,反映出了q形变的非线性行为对量子相干性的干扰以及对量子特性的影响。当q→1时,恢复为普通的线性理论。     

形变相干光场与级联型三能级原子相互作用中场的反聚束效应

建立了q形变光场与级联型三能级原子相互作用的非线性理论, 求得相互作用绘景中薛定谔方程的形式解及在其态下的期望值, 利用数值计算揭示了q形变对场与三能级原子相互作用中场反聚束效应的影响. 研究发现q偏离1的程度越大, q形变对场反聚束效应的调控能力越强, 反映出q形变的非线性行为对量子相干性的干扰以及对量子特性的影响. 当q→1时, 恢复为普通线性理论.     

处理原子-辐射场相互作用系统的变分方法

用Heisenberg-Weyl(简H-W)群直积SU(2)群上的相干态表述了原子-辐射场相互作用系统的非平衡态统计力学.引入一个新定义的含时分布函数,将非平衡态下密度矩阵所满足的von Neumann方程转化成可分离变量的偏微分方程,给出了方程的形式解,算符的平均值表示.本文还就便于作微扰展开的相互作用绘景作了讨论.     

ON AN APPROXIMATE FORM OF THE COUPLED EQUATIONS OF THE ORDER PARAMETER WITH THE WEAK ELECTROMAGNETIC FIELD FOR THE IDEAL SUPERCONDUCTOR

A simplified derivation of the macroscopic electrodynamic equations of Umezawa, Hancini et al. for superconductors is given in the framework of the closed time path Green's functions (CTPGF)using generalized Ward-Takahashi identities. It is shown that the forms of the equations obtained are the same for both thermoe quilibrium and nonequilibrium stationary states provided the electromagnetic field is weak and its effect on the modulus of the order parameter can be neglected. The statistical behavior of the states is completely specified in the equations by parameters which can be calculated by the method of CTPGF.     

时间反演对称和非平衡统计定常态(Ⅰ)

本文是作者从微观量子统计理论出发应用微观可逆性原理讨论非平衡统计定常态普遍性质的第一部份。文中给出了非平衡量子统计格林函数(闭路格林函数)在定常态上关于时间反演对称的表达方式。把生成泛函技术和时间反演对称结合起来,得到了具有时间反演对称性的非平衡统计定常态上统计格林函数和顶点函数所满足的时间反演对称关系。 关键词：     

原子核费密多体系统平均场近似的推广

本文应用先前得到的序参量——统计格林函数耦合方程组,对于原子核多费密子体系,系统地导出了它的平均场近似,Hartree-Fock近似和无规相位近似。并求出了相应近似下系统热力学势的明显表达式。本文的讨论也适用于处于平衡或非平衡定常态的其他多体系统。 关键词：     

ON A DYNAMIC THEORY OF QUENCHED RANDOM SYSTEM

A dynamical theory for quenched random system is developed in the framework of CTPGf. Tn steady states the results ob- tained coincide with Chose following from the quenched average of the free energy. The order parameter q, a matrix in general, becomes an integral part of the second order connected CTPGF.An equation to determine q is derived from the Dyson-Schwinger equation in this formalism. Some general properties of the CTPGF in a quenched random system are discussed.     

ON LOCALIZATION IN DISORDERED ELECTRON SYSTEMS

The field theory of Anderson localization of disordered electron systems is formulated in the framework of closed time path Green's functions (CTPGF). The properties of the mobility edge are studied by the renormalization group method and the density of states is found to be zero at the mobility edge.     

SYMMETRY AND WARD IDENTITIES FOR DISORDERED ELECTRON SYSTEMS

We study the field theory approach to Anderson localization in the framework of closed time path Green's function (CTPGF).The theory is found to be invariant under an Sp(2) group. Ward identities related to this symmetry are derived. A non-linear σ model arises as a consequence of the dynamical symmetry breaking caused by the imaginary part of the retarded Green's function.     

RESOLUTION OF PUZZLES IN PERTURBATION CALCULATION IN QUANTUM FIELD THEORY AT FINITE TEMPERATURES

It is shown that the difficulties met in the perturbation calculation of quantum field processes at finite temperatures are all due to improperness in the formulationaqd to certain ad hoc manipulations in previous versions of the theory. They disappear in the CTPGF (Closed Time Path Green's Function) formulation initiated by Schwinger, implying that the latter formulation brings about a more satisfactory theory.     

Ward-Takahashi Identity at Finite Temperature

A new real time formalism, based on the closed-time-path Green's function theory (CTPGF),is employed to obtain Ward-llfrkahashi identities of QED at finite temperature. It is shown that WT identity in coordinate space is of the same covariant form aa that in vacuum field theory. A perturbative check is provided to #how that in momentum spze, Takahashi's iden tities hold only in a weak sense.     

Quantum Electrodynamics at Finite Temperature:One-Loop Corrections to Electron Mass and Magnetic Moment

Employing the closed-time-path Green's function formalism (CTPGF), the electron selfenergy and vertex function at finite temperature are derived at one-loop level. The so-called "double termn" does not appear in our approach and thus, the unitarity of the theory is ensured automatically. The temperature-dependent mass and vertex corrections are dispersive due to the existence of electron-positron pair background. In the nonrelativistic limit, the explicit forms of shifts due to temperature of both mass and Lande's g factor are given, and their low temperature (T<>m) limits are discussed.