共查询到20条相似文献,搜索用时 62 毫秒
1.
构造出了一种新的奇偶非线性相干态, 并借助于数值计算方法研究了它们的压缩、振幅平方压缩、反聚束和相位概率分布等非经典性质. 结果表明, 与通常的奇偶相干态和非线性奇偶相干态不同, 在参数|λ|的不同取值范围内, 新的奇偶非线性相干态在Y1和Y2两个方向均可呈现振幅平方压缩效应, 而压缩效应仅在偶非线性相干态的X2方向上呈现, 反聚束效应仅在奇非线性相干态中呈现. 另外, 通过研究新的奇偶非线性相干态相位概率分布, 发现新的奇偶非线性相干态具有完全不同的量子干涉特性.
关键词:
新的奇偶非线性相干态
压缩效应
反聚束
相位概率分布 相似文献
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多光子非线性过程中的振幅平方压缩 总被引:4,自引:0,他引:4
本文研究了多光子非线性光学过程中的振幅平方压缩,证明了K光子么正算符Sk(z)(K>2)对非真空相干态的作用在—级近似下会产生振幅平方压缩.以及Sk(z)(K>2,K≠4)对真空态的作用不会产生振幅平方压缩.发现4个光子么正算符S4(z)对真空态的作用可以产生振幅平方压缩,这表明振幅平方压缩是一种独立于二阶压缩、反聚束以及亚泊松统计分布的新的光场非经典效应. 相似文献
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构造出了有限维Hilbert空间Roy型奇偶非线性相干态, 讨论了它们的正交归一完备性和振幅平方压缩效应. 研究表明, 在此空间中Roy型奇偶非线性相干态是归一完备的, 但不具有正交性; 当复参数相位角θ满足一定条件时它们存在振幅平方压缩效应, 同时导出了压缩条件与参数s,r以及函数f(n)之间的关系. 最后借助于数值计算, 发现对于5维(或7维)Hilbert空间中Roy型偶(或奇)非线性相干态, 当参数θ和Lamb-Dike参数η取某一给定值时, 在参数r变化的不同取值范围内, 它们均可以呈现振幅平方
关键词:
有限维Hilbert空间
Roy型非线性相干态
奇偶非线性相干态
振幅平方压缩 相似文献
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卢道明 《原子与分子物理学报》2008,25(4):875-880
利用数值计算方法,研究了有限维Hilbert空间一种新的奇偶非线性相干态的反聚束效应.研究结果表明:各有限维Hilbert空间新的偶非线性相干态均不出现反聚束效应.但各有限维Hilbert空间新的奇非线性相干态均可出现反聚束效应. 相似文献
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相干态的叠加态的量子统计性质 总被引:5,自引:2,他引:3
本文研究了相干态的叠加态的量子统计性质.结果表明,相干态的叠加态仅存在奇次幂的高阶压缩效应,而不存在偶次幂的高阶压缩效应.给出了高阶压缩和高阶反聚束效应与叠加系数间的函数关系.高阶压缩要求叠加系数的辐角取值满足cosθ>exp(-2|α|2),而高阶反聚束效应则要求0.5π<θ<1.5π.奇偶相干态的有关结果均作为特例应包含在本文的一般结论之中. 相似文献
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q变形非简谐振子奇偶广义相干态的高阶压缩效应及反聚束效应 总被引:2,自引:0,他引:2
研究了q变形非简谐振子奇偶广义相干态的高阶压缩效应和反聚束效应,并就q变量[χ]的两种不同表示情况进行了讨论.数值计算结果表明,q变形非简谐振子奇偶广义相干态均可呈现奇次方阶压缩效应和反聚束效应,这与谐振子情况的光学统计特性是不同的. 相似文献
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研究了一种新的非线性相干态的振幅平方压缩效应,给出了出现振幅平方压缩的条件,数值计算结果表明,该量子态呈现出振幅平方压缩效应,并且压缩效应与复参数β有关。 相似文献
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文章讨论了领头项奇偶相干态的非经典特性,得出了产生压缩效应和反聚束效应的条件,它们与奇偶相干态是不同的。 相似文献
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SONG Tong-Qiang 《理论物理通讯》2005,43(6):1107-1110
The four-particle EPR entangled state | p,χ2,χ3,χ4〉is constructed. The corresponding quantum mechanical operator with respect to the classical transformation p→eλ1p, χ2→
eλ2χ2, χ3→eλ3χ3, and χ4→eλ4χ4 in the state |p,χ2 ,χ3 ,χ4〉is investigated, and the four-mode realization of the
SU(1,1) Lie algebra as well as the corresponding squeezing operators are
presented. 相似文献
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Ji-Suo Wang Jian Feng Yun-Feng Gao Tang-Kun Liu Ming-Sheng Zhan 《International Journal of Theoretical Physics》2003,42(1):89-98
Based on Roy and Roy's work (Roy, B. and Roy, P. (2000). Journal of Optics B: Quantum Semiclass. Opt.
2, 65), a new type of even and odd nonlinear coherent states (NCSs) are defined. They result from Schrödinger cat states for deformed field. Using the numerical method, we study nonclassical properties of the new even and odd NCSs. It is shown that quantum statistical properties of the new even and odd NCSs are quite different from those of the usual even and odd coherent states (CSs). It is found that the squeezing only consists in the new even NCS, and the amplitude-squared squeezing and antibunching effect appear for both new even and odd NCSs in some ranges of ||. 相似文献
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We propose an entangled fractional squeezing transformation (EFrST) generated by using two mutually conjugate entangled state representations with the following operator: e - i α ( a 1 ? a 2 ? + a 1 a 2 ) e i π a 2 ? a 2 ; this transformation sharply contrasts the complex fractional Fourier transformation produced by using e - i α ( a 1 ? a 2 ? + a 2 ? a 2 ) e i π a 2 ? a 2 (see Front. Phys. DOI 10.1007/s11467-014-0445-x). The EFrST is obtained by converting the triangular functions in the integration kernel of the usual fractional Fourier transformation into hyperbolic functions, i.e., tanα → tanhα and sinα → sinhα. The fractional property of the EFrST can be well described by virtue of the properties of the entangled state representations. 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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熵测不准关系与光场的熵压缩 总被引:27,自引:3,他引:24
用熵作为光场量子涨落的量度,根据熵测不准关系,建立了熵压缩的概念,具体研究了光场与原子相互作用时的熵压缩,结果显示,熵压缩实现了对光场压缩效应的高灵敏量度。 相似文献
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WU Qin FANG Mao-Fa LI Shao-Xin LI Ying HU Yao-Hua 《理论物理通讯》2008,50(12):1411-1416
The entropy squeezing properties for a two-level atom interacting with a two-mode field via two different competing transitions are investigated from a quantum information point of view. The influences of the initial state of the system and the relative coupling strength between the atom and the field on the atomic information entropy squeezing are discussed. Our results show that the squeezed direction and the frequency of the information entropy squeezing can be controlled by choosing the phase of the atom dipole and the relative competing strength of atom-field, respectively. We find that, under the same condition, no atomic variance squeezing is predicted from the HUR while optimal entropy squeezing is obtained from the EUR, so the quantum information entropy is a remarkable precision measure for the atomic squeezing in the considered system. 相似文献
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We discuss the entropy generation in quantum tunneling of a relativistic particle under the influence of a time-varying force with the help of squeezing formalism. It is shown that if one associates classical coarse grained entropy to the phase space volume, there is an inevitable entropy growth due to the changes in position and momentum variances. The entropy change can be quantified by a simple expression S=ln cosh 2r, where r, is the squeeze parameter measuring the height and width of the potential barrier. We suggest that the universe could have acquired its initial entropy in a quantum squeeze from nothing and briefly discuss the implications of our proposal. 相似文献
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Qauntumtheoryoftwo-photonabsorptioninadrivenF-PcavitywiththefeedbackofphotonfluxLIUJiaren;WAdeYuzhu(JointLaboratoryforQuantum... 相似文献
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本文研究了在两个耦合的量子点和腔QED系统中的双模激子的压缩性质.讨论了不同的初始光场对双模激子的正常压缩与和压缩的影响.计算表明,当初始态光场制备在相干态时,双模激子既不存在正常压缩,也不存在和压缩,这说明双模激子振辐的两个正交分量具有相同的量子涨落;然而,当初始腔场处于压缩真空态时,无论是正常压缩还是和压缩,双模激子振辐的两个正交分量总有一个存在压缩.这意味着量子噪声能被有效的得到抑制.此外,两种情形下的最大压缩都由初始腔场的压缩因子r决定.经过比较,我们还发现双模激子的正常压缩比和压缩大. 相似文献