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Continuous Variable Entanglement and Violation of Bell Inequality for Two Modes in a Three-Level Cascade Atomic System 下载免费PDF全文
Continuous variable entanglement and violation of Bell inequality for two modes are investigated in a three-level cascade atomic system. Entanglement of the system is demonstrated according to the entanglement criterion [Phys. Rev. Lett. 84 (2000)2722]. Violation of Bell inequality is studied within the framework of a quantum theory of multiwave mixing. It is shown that there are some states that are entangled but do not violate the Bell inequality. 相似文献
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三能级电磁感应透明中辐射场的量子统计特性 总被引:7,自引:4,他引:3
对Λ型三能级原子电磁感应透明(EIT)过程中辐射场的二阶相干度进行了研究。理论分析表明,在电磁感应透明系统中,由于原子的相干效应导致其上能级共振荧光场的二阶相干度将呈现单光子场的量子统计特性。并对其随耦合场强度和探测光失谐的变化进行了详细的分析和讨论,结果发现:在|Ω|〉(Γ2+Γ3)/2情况下.采用较弱的耦合光功率(由托比频率Ω表征)及较大的探测光失谐,在较长时间延迟范围内,二阶相十度保持小于1,更利于实现非经典场的量子统计行为;相反,在|Ω|≤(Γ2+Γ3)/2情况下,探测光的失谐量越小,越利于获得二阶相干度小于1的量子统计光场。南此可见选取合适的参量可优化电磁感应透明过程中单光子场的量子统计特性。 相似文献
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GAO Yun-Feng FENG Jian ZHANG Gui-Ming 《理论物理通讯》2007,47(1):131-134
The cavity field spectrum of a cascade three-level atom interacting with single-mode field with Kerr-like medium in the cavity is investigated. The numerical results for the initial field in pure number state, coherent state and squeezed vacuum state are calculated, respectively. It is found that the Kerr-like medium affects the spectral structure even though the initial field is in vacuum when the atom is in upper level. In the case of strong input field, the number state spectrum shows two peaks with different heights; and the superposition state spectrum shows a multipeak structure with an equal distance of two neighboring peaks. The spectral "central frequency" shifts away from the resonant frequency with the increasing of average photon number. 相似文献
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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. 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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We show that it is possible to localize a three-level cascade atom under the resonance condition when it passes through a standing-wave field. The localization peaks appear at the nodes of the standing-wave field, the detecting probability is 50% in the subwavelength domain, and the peaks are narrower on the resonance than the off- resonance. The absorption is the same as that in the usual two-level medium at the nodes and is greatly suppressed outside the nodes due to the Autler-Townes splitting. This is in sharp contrast to the lambda scheme, in which the localization is impossible under the same resonance condition due to the depletion of population of the initial state by the probe field at the nodes and the electromagnetically induced transparency outside the nodes. 相似文献
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Violations of Bell inequality, Cauchy-Schwarz inequality and entanglement in a two-mode three-level atomic system are investigated. It is shown that there are some states, which are entangled but do not violate Bell inequality in this system. Moreover, the relations of violations of Bell inequality, Cauchy-Schwarz inequality, and entanglement are discussed in detail. 相似文献
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We consider the problem of an atomic three-level system (in a ladder configuration) interacting with a radiation field. Assuming a coherent state as the initial state, we solve exactly the time evolution of the system. We discuss the appearance of atomic squeezing and calculate the atomic spin squeezing and the atomic entropy squeezing. We show that both parameters predict similar angular and time dependences. 相似文献
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Spatial Splitting and Intensity Suppression of Four-Wave Mixing in V-Type Three-Level Atomic System 下载免费PDF全文
We illustrate our experimental observation of coexisting the controllable spatial splitting and intensity suppression of four-wave mixing (FWM) beam in a V-type three-level atomic system. The peak number and separation distance of the FWM beam are controlled by the intensities and frequencies of the laser beams, as well as atomic density. 相似文献
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We add some useful formulations except for Ref. [4], then investigate the squeezing properties of the atomic collective dipole phase quadrature operators with respect to three-level atomic coherent state in detail. We mainly discuss two extreme cases concerning parameter α and β and obtain some interesting conclusions. 相似文献
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耦合三能级原子与光场相互作用中系统的动力学行为 总被引:14,自引:3,他引:11
讨论了包含两个全同的三能级原子之间偶极矩相互作用的Jaynes-Cummings模型,并就Λ,Ξ和V三种能级构型建立了系统的动力学方程,特别在能级简并情况下讨论了具有Λ型能级的两个原子之间偶极相互作用及原子的初态和系统的失谐量对光场的统计性质和原子行为的影响。 相似文献
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YANG Wen-Xing LI Jia-Hua JIN Li-Xia 《理论物理通讯》2004,42(10)
We discuss the generation of certain kinds of multi-component entangled states for three-level atomic system with hyperfine structure. The method proposed here is based on the interactions of dispersive cavity with only one atom driven by a strong classical field. It is shown that, with a judicious choice of the cavity detuning and applied coherent field detuning, the atom can interact dispersively with the quantized field but the classical driving field gives rise to the creation or destruction of photons conditional on the state of the system. In comparison with previous schemes,our method is likely to be extremely easy to realize in practice 相似文献
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Optics and Spectroscopy - The possibility of inducing population gratings in a three-level resonant medium using a pair of unipolar attosecond pulses that do not overlap in the medium has been... 相似文献
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YANGWen-Xing LIJia-Hua JINLi-Xia 《理论物理通讯》2004,42(4):517-520
We discuss the generation of certain kinds of multi-component entangled states for three-level atomic system with hyperfine structure. The method proposed here is based on the interactions of dispersive cavity with only one atom driven by a strong classical field. It is shown that, with a judicious choice of the cavity detuning and applied coherent field detuning, the atom can interact dispersively with the quantized field but the classical driving field gives rise to the creation or destruction of photons conditional on the state of the system. In comparison with previous schemes,our method is likely to be extremely easy to realize in practice 相似文献
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The magnetic hyperfine field B
hf for Cd in the Heusler alloy Pd2MnSn at the site of chemically introduced Ag has been investigated by PAC following the – decay of 111Ag. Sign and temperature dependence of B
hf have been determined. Comparison of the result B
hf(T=0)=+8.0(1) T with earlier data and ab-initio band structure calculations leads to the conclusion that the Ag activity has been incorporated at the Mn site. 相似文献