共查询到20条相似文献,搜索用时 140 毫秒
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借助于数值对角化方法,研究了非旋波近似下J-C模型中原子的压缩效应,结果表明,在近可积区能观察到此种效应及基周期衰变与回复现象,而在远离近可积区这些特征消失。 相似文献
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应用数值计算方法,讨论双光子J-C模型中可积性与非经典效应间的关系。不作旋转波近,破缺可积怀的因素,主要来自虚光场项。 相似文献
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在一次效应的基础上,本文以n=2能级为例,计算了氢原子的二次斯塔克效应.计算结果表明,考虑了二次效应以后,能量只相对于一次效应有一移动而并不继续发生分裂,从而很好地解释了氢原子赖曼线系第一条谱线在电场作用下分裂为三条的现象. 相似文献
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在本文中,我们研究了多光子自由-自由跃迁中原子的修饰效应。我们用不同于Joachain et al的方法处理激光场中氢原子基态波函数并给出自由-自由跃迁微分截面。在数值计算的基础上分析了微分截面随光子能量以及随散射角的变化规律,结果表明当激光场较强时,原子的修饰效应很大,特别是在小动量转移区,原子的修饰效应非常显著。我们的结果还表明即使散射电子与激光场交换的净光子数等于零,原子的修饰效应照样很大。进一步分析我们还发现,考虑原子的修饰效应后,微分截面随散射角和光子能量变化而变化所特有的振荡加剧。 相似文献
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利用朗之万方程理论证明,在多单光子激光振荡的线性区域,泵浦统计、原子相干性及原子位相起伏可导致光子数压缩效应。 相似文献
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Some nonclassical features, including photon antibunching, atomic squeezing and quantum collapse-revival phenomenon, were numerically studied in thp vacuum field Jaynes-Cummings model (JCM). The influence of the initial atomic coherence on these features was discussed. It is shown that the squeezing can appear only if the atom is initiaJly prepared in the coherent state, and photon antibunching cHn occur if the atom is initially in the excited state or the coherent one. The effect of the virtual-photon field was studied in JCM without the rotating-wave approximation (ftWA). We have shown that even undh the condition in which RWA is considered to be valid, there are significant effects on the nonc1assical features due to the interference between the virtual-photon processes and the real-photon processes. Quantum dynamics of JCM without RWA was aJso studied. We showed that regular dynamical behavior is exhibited in the cases rather close to the integrable limits, and irregular dynamical behavior is presented in the cases far from the integrable limits; in addition, all the nondassical features disappear in the cases far from the integrable limits. 相似文献
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腔内混合态原子系统中辐射场的压缩效应 总被引:19,自引:2,他引:17
本文应用熵最大原理,假定腔内二能级原子起初就没有关于系统所处态的任何信息,研究了腔内原子与腔场相互作用的压缩行为,得出了原子初始处于任意统计混合态下,当初始激发足够强时,辐射场将产生极其接近于纯态情况在相同激发时的强压缩现象的重要结果,同时还讨论了产生压缩的混态范围。 相似文献
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The squeezing phenomenon is investigated in optical parametric processes and in Raman and hyper-Raman scattering. It is related to the antibunching effect and the sub-poissonian statistics of optical fields in these processes, and it is demonstrated that squeezing accompanies antibunching very often, but not always. In some cases squeezing may occur and antibunching may not and vice versa. 相似文献
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Generation of strong stationary optical and mechanical squeezing is proposed for the linear‐and‐quadratic optomechanical system, where two cavity modes induce linear and quadratic optomechanical couplings, respectively. Through the linearization treatment, linearized coupling between cavity mode and mechanical mode and the mechanical parametric amplification process are achievable and controllable by independent driving lasers. Optical and mechanical squeezing are generated following different mechanisms. Optical squeezing works in the strong coupling regime, and mechanical amplification would push the system close to instability threshold, which could deeply improve ponderomotive squeezing even significantly beyond the 3 dB squeezing limit. Mechanical squeezing is generated based on the reservoir engineering method, where parametric amplification induces the squeezing transformation of mechanical mode; and linearized coupling, which operates in the red‐sideband and weak coupling limits, induces the ground‐state cooling of transformed mechanical mode. Finally, the original mechanical mode would be squeezed, which could also exceed 3 dB limit. 相似文献
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研究了在压缩粒子数态(SNS)中振幅k次幂的压缩效应(AKPS),导出有关压缩效应的普遍性公式,并用数值计算的方法,得到了前四次幂k=1,2,3和4的有关压缩特性,结果表明:这种压缩特性在光学通信领域有着一定的应用前景。
关键词: 相似文献
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Quantum entanglement and nonlocality properties of a family of
two-mode Gaussian pure states have been investigated. The results
show that the entanglement of these states is determined by both the
two-mode squeezing parameter and the difference of the two
single-mode squeezing parameters. For the same two-mode squeezing
parameter, these states show larger entanglement than the usual
two-mode squeezed vacuum state. The violation of Bell inequality
depends strongly on all the squeezing parameters of these states and
disappears completely in the limit of large squeezing. In
particular, these states can exhibit much stronger violation of
local realism than two-mode squeezed vacuum state in the range of
experimentally available squeezing values. 相似文献
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克尔介质中压缩真空场与耦合双原子依赖强度耦合系统光场的压缩特性 总被引:2,自引:0,他引:2
研究了存在克尔介质时依赖强度耦合单模压缩真空场与耦合双原子非共振相互作用系统光场的压缩性质,运用数值方法讨论了系统参量对光场压缩性质的影响。结果表明:克尔介质、失谐量、原子间相互作用、光场初始压缩因子对光场的压缩性质有较大的影响。随原子间偶极偶极相互作用的增大,光场的压缩随时间逐渐变浅,压缩的次数减少;随克尔效应或失谐量的增大,光场的压缩程度先逐渐变浅后增强、压缩次数先减少后增多;当光场初始压缩因子较小时,光场压缩程度较小,当光场初始压缩因子较大时,光场压缩程度增大;而原子的初始状态对光场的压缩程度没有明显的影响。 相似文献
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Dong Yan Lijun Song Jian Ma Xiaoguang Wang 《International Journal of Theoretical Physics》2010,49(4):861-869
We investigate the global and the local spin squeezing in a weakly coupled quantum kicked tops system. Two different situations
are considered: (i) N=1 and (ii) N=30 for each subsystem, corresponding to quantum and classical cases, respectively. In the first case, since the two subsystems
have no spin squeezing, the global squeezing completely originates from quantum correlations. For the second one, the global
spin squeezing is enhanced over the local one. Due to the chaotic nature of the system, the spin squeezing is sensitive to
the initial state. In chaotic region, the squeezing vanished time is much shorter than that in the regular region. 相似文献
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In this context, we introduce and investigate the properties of the nonlinear negative binomial state (the state which interpolates between the nonlinear coherent and the number states). Mainly we concentrate on the statistical properties for such state where we have discussed two different cases of squeezing phenomenon. The first case is the normal squeezing while the second is the amplitude squared squeezing, further the second order correlation function is also considered. Our discussion have been extended to include the quasi-probability distribution functions (W-Wigner and Q-functions). The quadrature distribution and the phase properties in Pegg-Barnett formalism besides the phase variances are considered. Examination of the resonance fluorescence against the present state is given (single atom and thermodynamic limit). It has been shown that the atomic inversion is sensitive to any variation in the nonlinear negative binomial number m. 相似文献
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奇偶相干态中测量相位算符的涨落及其压缩 总被引:14,自引:0,他引:14
利用Barnett和Pegg提出的测量相位算符讨论了奇偶相干态中的相位涨落及其高阶涨落,在测不准关系和高阶测不准关系基础上给出了测量相位压缩和高阶压缩的二类定义,并用这二类定义研究了奇偶相干态中测量相位的二阶和高阶压缩情况。 相似文献