共查询到20条相似文献,搜索用时 109 毫秒
1.
运用全量子理论并结合数值计算方法,研究了Kerr介质腔中处于Bell态的两个全同二能级纠缠原子与双模纠缠相干光场相互作用系统的原子偶极压缩特性.讨论了双原子体系的初态、光场的平均光子数、双模纠缠相干光场的纠缠程度以及Kerr介质与双模光场的耦合强度对原子偶极压缩特性的影响.结果表明:双原子体系的初态为|β11>时,不会出现偶极压缩效应;初态为|β00>,|β01>或|β10>时在一定条件下可能出现原子压缩效应,且此时原子压缩的特性与Kerr介质与双模光场的耦合强度、初始光场的平均光子数、双模纠缠相干光场的纠缠程度有关.
关键词:
量子光学
Bell态
双模纠缠相干光场
Kerr介质 相似文献
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运用求解Schrdinger方程和数值计算方法,研究了处于Bell态的两个全同二能级纠缠原子与双模纠缠相干光场相互作用系统的光场压缩特性,分析了双模纠缠相干光场的纠缠程度、双模纠缠相干光场的初始平均光子数对光场压缩性质的影响,以及两纠缠原子的相互作用强度对光场压缩性质的影响.结果表明:若初始时刻原子处在Bell态|β11〉,则不出现光场的压缩效应,而处在另外三种Bell态时,在一定的条件下均可呈现光场的压缩效应.光场压缩效应不仅与初始光场的平均光子数以及原子的初态有关而且与双模纠缠相干光场的纠缠程度有关,但与两纠缠原子的相互作用强度的大小没有明显的关系. 相似文献
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借助于双模压缩真空态在EPR纠缠态表象中的表示,研究了用双模压缩真空态作为量子通道 实现任意的单模和双模量子态的远程传输.
关键词:
量子隐形传态
EPR纠缠态
压缩真空态 相似文献
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三能级原子与奇偶纠缠相干光作用的光场压缩 总被引:8,自引:2,他引:6
采用求解薛定谔方程和数值计算方法,研究了V型三能级原子与双模奇偶纠缠相干光场相互作用过程中的光场压缩效应,讨论了压缩效应与双模奇偶纠缠相干光场的纠缠程度、系统失谐量、双模光场的平均光子数和原子基态概率幅的依赖关系。结果表明:光场压缩效应与双模奇偶纠缠相干光场的纠缠程度、失谐量、平均光子数和原子初态相关联:双模纠缠相干光场处于非纠缠状态时的光场压缩量比光场处于纠缠状态时要大;原子处在单纯的基态或激发态时光场都有明显的压缩现象出现;而原子初态中基态和激发态的概率幅较接近时无光场压缩现象;无论光场是否处于纠缠态,只有两模平均光子数接近时,光场才会出现压缩效应。 相似文献
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量子相干性作为量子力学一个最显著的特征,被认为是量子信息过程中很重要的一种量子资源.单模压缩态和双模压缩态(Einstein-Podolsky-Rosen纠缠态)均具有量子相干性,在制备和传输过程中的量子相干性对于实际应用具有重要意义.利用平衡零拍探测重构量子态的协方差矩阵,本文定量分析了量子态制备过程中的不完美以及信道传输损耗对单模和双模压缩态量子相干性的影响.实验证明量子态的压缩和纠缠特性及量子相干性对损耗均是鲁棒的.特别地,压缩和纠缠特性会随着量子态制备过程中热光子数的增大而减小,直至消失,而当压缩和纠缠均已消失时,量子相干性依然存在.实验结果为压缩态、纠缠态光场的量子相干性作为量子资源在量子信息过程中的应用提供了参考. 相似文献
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基于对坐标表象、动量表象及相干态表象完备性关系式的正规乘积内纯高斯积分形式的分析,阐述了利用有序算符内的积分技术构建量子力学新表象的思路和方法,并具体以单模坐标-动量中介表象、双模纠缠态表象和双模相干纠缠态表象的构建为例进行了论述. 相似文献
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Duc Minh Truong Hoai Thi Xuan Nguyen An Ba Nguyen 《International Journal of Theoretical Physics》2014,53(3):899-910
In this paper, we study some higher-order nonclassical properties and intermodal entanglement that may arise in the so called two-mode photon-added displaced squeezed state. We derive analytical expressions for the degree of sum squeezing and difference squeezing, which are interesting kinds of two-mode squeezing, as well as for the degree of antibunching to any orders. We also examine the degree of entanglement between the two modes using the existing Hillery-Zubairy criterion. Based on the derived expressions we analyze in detail the behavior of these nonclassical effects and entanglement depending on the parameters involved. 相似文献
12.
In this paper, we study quadrature squeezings of
two Bose-Einstein condensates with collision and nonclassical
properties of pair entanglement in four wave mixing in
Bose-Einstein condensates. With the aid of a numerical method, we
find that the two modes (pair entanglement modes) a1 and a2 may exhibit quadrature squeezing, in which they are affected by
the initial phase. It is shown that the two pump modes exhibit
the same super-Poissonian distribution. The analysis for the
mode-mode correlation shows that there always exists a violation
of the Cauchy-Schwartz inequality, which means that correlation
between the two pump modes is nonclassical. 相似文献
13.
Priya Malpani Nasir Alam Kishore Thapliyal Anirban Pathak Venkatakrishnan Narayanan Subhashish Banerjee 《Annalen der Physik》2020,532(1):1900337
The effect of two quantum state engineering processes that can be used to burn a hole at vacuum in the photon number distribution of quantum states of radiation field is compared using various witnesses of lower- and higher-order nonclassicality as well as a measure of nonclassicality. Specifically, the modification in nonclassical properties due to vacuum state filtration and a single photon addition on an even coherent state, binomial state, and Kerr state are investigated using the criteria of lower- and higher-order antibunching, squeezing, and sub-Poissonian photon statistics. Further, the amount of nonclassicality present in these engineered quantum states having enormous applications in continuous variable quantum communication is quantified and analyzed by using an linear entropy-based entanglement potential. It is observed that all the quantum states studied here are highly nonclassical, and the hole-burning processes can introduce/enhance nonclassical features. However, it is not true in general. A hole at vacuum implies a maximally nonclassical state (as far as Lee's nonclassical depth is concerned), but a particular process of hole burning at vacuum does not ensure the existence of any particular nonclassical feature. Specifically, lower- and higher-order squeezing are not observed for photon-added and vacuum filtered even coherent states. 相似文献
14.
用Von Neumann熵研究了附加克尔介质的压缩真空场与二能级原子依赖强度耦合相互作用量子体系的量子纠缠特性.讨论了初始压缩真空场的压缩度以及克尔非线性作用的强度对该量子体系纠缠特性的影响.结果表明,克尔介质的非线性作用的强弱可以改变体系量子纠缠的周期性;在初始压缩度较大(r=5)时,克尔介质的非线性作用可导致原子与场持续地处于最大纠缠态,无消纠缠态或持续地处于消纠缠态.
关键词:
压缩真空态
克尔介质
依赖强度耦合J-C模型
Von Neumann熵
量子纠缠 相似文献
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Quantum entanglement between the two-mode fields and atomic entropy squeezing in the system of a moving atom interacting with two-mode entangled coherent field 下载免费PDF全文
This paper investigates the entropy squeezing of a moving two-level
atom interacting with the two-mode entangled coherent field via
two-photon transition by using an entropic uncertainty relation and the
degree of entanglement between the two-mode fields by using quantum
relative entropy. The results obtained from numerical calculation
indicate that the squeezed period, the duration of entropy squeezing
and the maximal squeezing can be controlled by appropriately
choosing the intensity of the light field, the atomic motion and the
field-mode structure. The atomic motion leads to the periodic
recovery of the initial maximal degree of entanglement between the
two-mode fields. Moreover, there exists a corresponding relation
between the time evolution properties of the atomic entropy
squeezing and those of the entanglement between the two-mode fields. 相似文献
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Meng Xiang-Guo Wang Ji-Suo Li Yan-Ling 《International Journal of Theoretical Physics》2007,46(5):1205-1214
In this paper, a new kind of even and odd nonlinear coherent states (NLCSs) are introduced. Some nonclassical properties of
the states are investigated. It has been found that the new even and odd NLCSs exhibit quadrature squeezing and amplitude-squared
squeezing in the Y
2 direction, however the new odd NLCSs only display sub-Poissonian behaviour. The results show that the nonclassical properties
of the new even and odd NLCSs are rather different from those of the usual even and odd coherent states and NLCSs.
PACS numbers:42.50.-p, 03.65.-w 相似文献
19.
The interaction between a ◊-type four-level atom and a single-mode field in the presence of Kerr medium with intensity-dependent coupling involving multi-photon processes has been studied. Using the generalized (nonlinear) Jaynes-Cummings model, the exact analytical solution of the wave function for the considered system under particular condition, has been obtained when the atom is initially excited to the topmost level and the field is in a coherent state. Some physical properties of the atom-field entangled state such as linear entropy showing the entanglement degree, Mandel parameter, mean photon number and normal squeezing of the resultant state have been calculated. The effects of Kerr medium, detuning and the intensity-dependent coupling on the temporal behavior of the latter mentioned nonclassical properties have been investigated. It is shown that by appropriately choosing the evolved parameters in the interaction process, each of the above nonclassicality features, which are of special interest in quantum optics as well as quantum information processing, can be revealed. 相似文献