利用驱动单个原子制备腔场的纠缠相干态

提出一种利用经典场驱动单个二能级原子与一双模腔场相互作用制备腔场的纠缠相干态的方案。通过对原子的激光操纵 ,包括Stark效应和Rabi频率的交替控制 ,使原子与双模腔场相互作用后演化为纠缠态 ,再对原子进行选态测量即可获得所要制备的量子态。     

通过驱动单个原子实现类自旋的腔场GHZ态

提出一种利用经典场驱动单个二能级原子与 3个单模腔场发生色散相互作用 ,最后对原子进行选择性测量 ,从而实现类自旋的腔场GHZ态的制备。利用现有的腔QED技术 ,加上对原子的激光操纵—Stark效应和Rabi频率的交替控制 ,可以在实验上实现上述GHZ态的制备     

通过驱动单个原子实现类自旋的腔场GHZ态

提出一种利用经典场驱动单个二能级原子与3个单模肠场发生色散相互作用,最后对原子进行选择性测量,从而实现类自旋的腔场GHZ态的制备。利用现有的腔QED技术,加上对原子的激光操纵-Stark效应和Rabi频率的交替控制,可以在实验上实现上述GHZ态的制备。     

超高斯啁啾脉冲中里德堡钾原子的相干激发

采用含时多态展开方法(TDML),对超高斯频率啁啾的激光场中的里德堡钾原子布居数相干迁移进行了计算研究,结果表明:在合适的激光参数下,采用超高斯啁啾脉冲可以实现布居数在量子态间的有效跃迁.通过对该体系动态Rabi频率的分析,得出:实现布居数囚禁的关键不在于具体Rabi频率的大小,而在于实现Rabi频率的适时跳转.     

三能级Σ型原子系统中的光放大

本文分析了一个被相干和非相干泵浦的三能缘原子系统的稳态增益和激光特性得出产生无反转激光的条件用激光的强度，该系统能实现有粒了数反转激光到无粒子数反转激光的转变。     

三能级∑型原子系统中的光放大

本文分析了一个被相干和非相干泵浦的三能级原子系统的稳态增益和激光特性,得出产生无反转激光的条件和激光的强度。该系统能实现有粒子数反转激光到无粒子数反转激光的转变。     

开放的V型非共振无反转激光系统的瞬态演化

从电偶极近似和旋波近似下开放的V型无反转激光系统的密度矩阵运动方程出发，利用数值计算方法研究了探测场和驱动场失谐情况下系统原子响应的瞬态演化规律，并与探测场和驱动场皆共振时的情况进行了比较，我们发现失谐对原子响应的演化规律有显著影响．     

开放的梯型三能级系统中自发辐射诱导相干对无粒子数反转激光的影响

研究表明,在开放的梯型三能级系统中,无论是否考虑非相干泵浦,考虑自发辐射诱导相干（SGC）时系统产生的无粒子束反转激光（LWI）总是明显大于不考虑SGC时的情况.并且,SGC的强度在一定范围内时,系统在无非相干泵浦场的情况下会产生比有非相干泵浦时更大的无反转增益,而相应的封闭系统在无非相干泵浦场时对任意强度的SGC都无法产生增益.     

双激光位相差对石墨层中声子增益的影响

通过修正的泛函积分方法研究两束激光对石墨层中原子位移涨落的影响.计算表明:在激光场强和频率一定的情况下,适当调节激光场的相位差,可以使原子位移涨落随时间的变化率在有限的时间范围内为正值,这对应声子增益的过程.详细讨论了产生这种声子增益效应的机理,给出了产生声子增益的时间间隔.     

飞秒激光参数对三态梯度型分子态布居数的影响

 利用含时波包法研究并且首次量化了强飞秒泵浦-探测激光场中泵浦场强、泵浦波长和脉宽对三态梯度型K₂分子态布居数的影响。泵浦场强、泵浦波长和脉宽影响Rabi振荡,而Rabi振荡的变化又导致了基态和激发态布居数周期性变化。量化这3个激光场参数对激发态布居数的影响验证了此周期性变化规律,表明变化频率随着泵浦场强和脉宽的增大而变化。研究表明调节激光场参数可实现对态布居数的选择性分布,可以为实验上实现分子的光控制提供重要参考。     

Dynamics of a qubit—TLS system under resonant microwave driving

We demonstrate the effect of different coupling strengths between a microscopic two-level system(TLS)and a microwave field on the dynamics of a qubit—TLS system when the bipartite system is subject to resonant microwave driving.Rabi beating with a different TLSmicrowave coupling strength is demonstrated in simulations.Entanglement,quantified by the concurrence between the qubit and TLS,both for pure states and mixed states,is simulated.When decoherence is considered,entanglement of the bipartite system oscillates with damping and exhibits entanglement sudden death and/or entanglement sudden death and revival.     

The Modulation of Ionospheric Alfvén Resonator on Heating HF Waves and the Doppler Effect

0　IntroductionIthasbeenwellknownthattheformationofIonosphericAlfv啨ｎＲｅｓｏｎａｔｏｒ(IAR)isforthebreakdownofgeometricop tics.ItscentralregionliesneartheheightofF regionelectrondensitypeak .Andatthetypicalheightof 30 0 0kmexiststhemaximumgradientofAlfv啨ｎｖｅｌｏｃｉｔｙ ,whichleadstothereflec tionofshearAlfv啨ｎｗａｖｅｓａｎｄｐｒｏｄｕｃｅｓｔｈｅｕｐｐｅｒｂｏｕｎｄａｒｙｏｆｔｈｅｒｅｓｏｎａｔｏｒ.Likewise,thelowerboundaryoftheresonatorformsneartheheightof 2 0 0 30 0km .Thus,she…     

Numerical study of threshold gain behavior for a THz random laser in a two-dimensional active disordered medium with a three-level atomic system

By numerically solving Maxwell’s equations and rate equations in a two-dimensional (2D) active random media made of ruby grains with a three-level atomic system, the threshold gain behavior for a THz random laser is investigated. The spectral intensity variation with the pumping rate is calculated for both the transverse magnetic (TM) field and the transverse electric (TE) field. The computed results show that THz random lasing could occur in a 2D disordered medium for both the TM and TE cases. Further analysis reveals that the THz lasing threshold for TM fields is lower than that for TE fields.     

用染料激光增益增强弱增益拉曼模式的受激拉曼散射的经典理论

 建立了用染料激光增益增强弱拉曼模式的受激拉曼散射(SRS)的经典理论,详细给出了拉曼增益g_R,染料激光增益g_D和总损耗α的表达式,并在其推导过程中对经典理论作了修正,最后得到了激光增益和受激拉曼增益可以共同使SRS强度的指数部分快速增长的结果,可以很好地解释观察到的实验现象,并为其提供理论依据.     

微腔半导体激光器的多模行为

采用数值模似的方法讨论了微腔半导体激光器的多模行为。结果表明,通过调整微腔的结构,使激射模频率落在有源介质的增益谱峰处,并且使自发发射进入该模式的效率尽量大,可实现微腔半导体激光器的单模输出。     

Size-reduction of Rydberg collective excited states in cold atomic system

The collective effect of large amounts of atoms exhibit an enhanced interaction between light and atoms. This holds great interest in quantum optics, and quantum information. When a collective excited state of a group of atoms during Rabi oscillation is varying, the oscillation exhibits rich dynamics. Here, we experimentally observe a size-reduction effect of the Rydberg collective state during Rabi oscillation in cold atomic dilute gases. The Rydberg collective state was first created by the Rydberg quantum memory, and we observed a decreased oscillation frequency effect by measuring the time traces of the retrieved light field amplitude, which exhibited chirped characteristics. This is caused by the simultaneous decay to the overall ground state and the overall loss of atoms. The observed oscillations are dependent on the effective Rabi frequency and detuning of the coupling laser, and the dephasing from inhomogeneous broadening. The reported results show the potential prospects of studying the dynamics of the collective effect of a large amount of atoms and manipulating a single-photon wave-packet based on the interaction between light and Rydberg atoms.     

kerr介质中级联三能级原子与光场非共振相互作用过程中原子的动力学特性

本文导出了充满ｋｅｒ介质的高Ｑ腔中级联型三能级原子与双模ＳＵ（１，１）相干态场非共振相互作用系统的态矢量，并以此计算三能级原子布居概率随时间的演化，数值计算显示，ｋｅｒ效应产生与两能级原子不同的Ｒａｂｉ振荡特征，而ｋｅｒ效应与失谐的共同作用导致出现电子绝热跃迁转移现象。     

一个四能级相干驱动原子系统中的多透明窗

研究了在两个相干场驱动下呈现多透明窗特征的四能级原子系统. 该系统是N型四能级模型, 当只存在一个相干场时, 是典型的三能级V模型透明结构, 而在两个相干场的驱动下, 该系统呈现出两个透明窗口, 透明窗的位置、 宽度和吸收高度均可以通过调节驱动场的强度和失谐进行控制. 每个透明窗口在吸收最低时都伴随着高折射, 表明探测光的群速度在每个透明窗口都变慢了.