被克尔介质包围的∧型三能级原子的粒子布居几率

本文研究了被克尔（Ｋｅｒｒ）介质包围的∧型三能级原子的粒子布居几率随时间的演化，分析了光场频率与原子本征频率间的单光子失谐量和克尔介质对粒子布居几率的影响。     

被克尔介质包围的A型三能级原子的粒子布居几率

本文研究了被克尔(Kerr)介质包围的\型三能级原子的粒子布居几率随时间的演化,分析了光场频率与原子本征频率间的单光子失谐量和克尔介质对粒子布居几率的影响.     

量子Zeno效应对原子布居翻转的影响

在量子信息的研究中,量子Zeno效应(QZE)的研究对量子信息的处理有重要作用.针对原子—场相互作用系统,在Jaynes Cummings(JC)模型下,研究在不同测量时间间隔中,布居翻转与初态存活概率的变化趋势.同时得出在时间间隔足够小时,产生QZE,进而得出QZE对布居翻转的影响.     

量子Zeno效应对原子布居翻转的影响

在量子信息的研究中,量子Zeno效应（QZE）的研究对量子信息的处理有重要作用.针对原子—场相互作用系统,在Jaynes Cummings ( JC) 模型下,研究在不同测量时间间隔中, 布居翻转与初态存活概率的变化趋势.同时得出在时间间隔足够小时,产生QZE,进而得出QZE对布居翻转的影响.     

激光场强度对NO电子态粒子数布居影响的理论研究

用含时波包方法研究了激光场强度对NO各电子态上粒子数布居的影响.在计算中,采用了四态模型.利用分裂算符傅里叶变换方法求解Schrdinger方程,得到各个电子态的波函数,从而求得各个电子态上粒子数的布居.计算结果表明,不同强度的抽运光对各个电子态上粒子数布居会产生不同的影响.通过改变激光强度可以实现对电离产率的控制,这种思想对实现原子分子过程的激光操控具有重要意义.     

实现粒子布居高效转移的两种激光脉冲时序方案的理论研究

基于最近实验工作的结果(2010 Nat.Phys.6 265)即Danzl等在五能级M型级联系统中分别利用连续型和四光子型受激拉曼绝热通道(stimulated Raman adiabatic passage,STIRAP)实现了将Feshbach态上弱束缚的Cs2有效转移到其振转基态,本文理论研究了两种STIRAP方案实施的基本条件,解析推导系统的准暗态、绝热参数的具体形式并分析其存在的必要性,详细讨论布居转移效率对相关参量的依赖关系.通过比较激光脉冲的时序、中间能级的失谐量和自发辐射率、光场脉冲的幅值等诸多参量的不同影响,讨论方案各自的优缺点,找到了参量优化的方法以实现最高效的粒子布居数转移.与前人的实验结果相比,本文研究表明,实验观测值(约0.60)均低于理论预估最佳值(约0.97)的主要原因是受限于激发态能级的自发辐射率过大.该理论方案还可用于制备量子纠缠态,在量子逻辑门操控、量子信息传输等领域都有潜在的应用.     

超短激光脉冲的绝对相位对三能级Λ型原子布居的影响

通过数值求解含时薛定谔方程,研究超短激光脉冲与三能级Λ型原子相互作用过程中影响原子电离态跃迁几率的几个因素,如:绝对相位,啁啾率等.研究结果表明激光绝对相位、啁啾率的大小是关系态跃迁几率的重要因素,通过调节超短激光脉冲的绝对相位和啁啾率,可以将态跃迁几率控制到较大的水平.本文研究结果为实验上对态跃迁几率的控制提供了相关理论基础.     

三粒子W型态的几率隐形传送

提出一个三粒子W型态的量子隐形传送方案.此方案用一个二粒子缠结态和一个三粒子缠结态(两者均为非最大缠结态)作为量子信道,若接收者进行合适的幺正变换操作,可实现三粒子W型态的几率隐形传送.     

基于双核模型的粒子交换势能面与熔合几率的研究(英文)

研究了基于双核模型的粒子交换势能面.原子核的形变效应对于势能面的形状有较大的影响.在反应过程中,作为反应时间函数的动态形变的变化是显著的.通过求解主方程,对一些基于冷熔合机制的反应道的全熔合几率也进行了讨论. The Potential Energy Surface (PES) for particle exchange in Di nuclear system is studied in detail. It is found that the nuclear deformation effect can change the shape of PES significantly. The dynamical deformation as a function of the reaction time in the reaction process is investigated in a simple model and we found that its variation with time is dramatic. The fusion probabilities P-CN of some reaction channels based on the mechanism of cold fusion are also calculated.     

Phase amplitude decoupling in modulated structures

We examine under what conditions phase and amplitude modulations are decoupled in a modulated structure, within a Landau Ginzburg approach. For the general case of a pth order commensurability, the condition for phase amplitude decoupling depends on the leading anharmonic terms in the Landau Ginzburg free energy. For a 2Mth order leading anharmonic term, the case p = 2M is a border line case. For p > 2M, phase and amplitude are decoupled near the disordered-incommensurate transition temperature, while they are not for p < 2M. In the latter case decoupling occurs at lower temperatures. We discuss the case of deuterated thiourea, which exhibits a commensurate pinning for p = 9 at T = 191 K.     

Scale invariant amplitude modulated phase-only filtering

A new synthetic discriminant-function-based amplitude modulated phase-only filtering technique is proposed for scale invariant pattern recognition. This technique has been found to yield improved correlation output when compared with the alternate techniques. The proposed technique is inherently suitable for optical implementation using the currently available spatial light modulators. Simulation results confirm the effectiveness of the proposed technique.     

Aharonov-Bohm oscillation amplitude in small ballistic interferometers

Small-radius (110 nm) ring interferometers were fabricated by the local anodic oxidation of AlGaAs/GaAs heterostructures containing 2D electron gas. Measurements and modeling show that a small ring asymmetry, which is detected by an atomic force microscope, leads to a small amplitude of Aharonov-Bohm oscillations, while a stronger asymmetry completely suppresses these oscillations.     

Effect of linewidth on the phaseshifts in the scattering of weakly amplitude modulated light

When light which is weakly modulated in amplitude is scattered from a two-level system a phase-shift occurs. We have calculated this phase-shift for a Lorentzian lineshape, and find it depends strongly on linewidth. Expressions are given which would enable a realistic comparison between theory and experiment to be made.     

一种宽带幅度调制信号的自动检测方法

给出了一种自动检测解调谱线谱的方法。该方法是一种双门限检测过程,首先通过选择低的检测门限和利用线谱的形状特点进行线谱识别来完成第一次检测,延迟一段时间后利用该时刻前后多个时刻的解调谱的线谱识别情况剔除噪声、自动生成中间丢失的线谱来完成第二次检测。分析表明,此线谱检测方法并不需事先知道调制信号的幅值、根数、位置、起止时间等信息,却能在低信噪比下自动地以高检测概率和低虚警概率检测解调谱的线谱。     

The dependence of the quantum oscillation amplitude on spin splitting

The electron density of states of a semiconductor in magnetic field exhibits an oscillatory behaviour. The amplitude of these oscillations is studied theoretically as a function of the electron spin splitting. The amplitude is shown to be strongly reduced when the spin splitting is equal to the half of the orbital splitting ?ω, provided that the collision broadening of the electronic levels is large enough. This fact should be reflected in a similar reduction of the amplitude of various quantum oscillatory phenomena, e.g. Shubnikov-de Haas effect.     

Phase shift of the population oscillation and population trapping

Using our recently developed time-dependent multilevel approach, we have calculated the phase shift of the population oscillation of the excited potassium atom in frequency-modulated fields when the modulation amplitude is suddenly changed. The numerical results are in good agreement with the measurements. A new way of realizing population trapping is suggested.