共查询到20条相似文献,搜索用时 78 毫秒
1.
计算表明,与场的相干态类似的原子相干态,具有不同于场的相干态的压缩行为;进一步证明:直接类比于(?)(ξ)不能得到“原子压缩算符”. 相似文献
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位相相干态的数相高阶压缩 总被引:5,自引:0,他引:5
本文根据Pegg-Barnett的量了相位理论和Hong-Mandel的高阶压缩概念,研究了有限维空间谐振子位相相干态中粒子数和相位的高阶压缩效应,研究结果表明,在特定的条件下,位相相干态的粒子数和相位都可呈出最大程度的高阶压缩。 相似文献
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有限维Fock空间谐振子的奇偶相干态的高阶压缩 总被引:1,自引:0,他引:1
针对有限维Fock空间谐振子的奇偶相干态的高阶压缩特性,具体研究了在这种奇偶相干态中正交算符的任意阶压缩性质,研究结果表明,在特定条件下,正交算符在偶相干态中有2N阶压缩,且出现各阶最大压缩的条件完全相同。 相似文献
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通过保持非耗散介观LC电路的固有频率不变,而使电路参数作阶跃函数变化,就可将介观LC电路由初始的偶相干态制备到压缩偶相干态;在压缩偶相干态下,介观电路系统不仅有非经典的量子压缩效应,而且有非经典的反聚束效应.
关键词:
介观LC电路
单位阶跃函数
压缩算符
压缩偶相干态 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
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研究了振幅“薛定谔猫”态光场的方差压缩和熵压缩效应,讨论了方差压缩和熵压缩与相干态强度R和幅角θ之间的关系,并对两种压缩进行比较. 相似文献
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本文构造了以奇偶q相干态为特例的一般叠加q相干态|α,θ〉q=c(|α〉q+e^iθ|-α〉a),并研究了它的振幅M次方压缩性质,发现这种叠加态只存在振幅奇数次方压缩效应。并数值计算了叠加系娄籴形参数对压缩的影响。 相似文献
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本文研究了两个二能级原子通过双光子跃迁与压缩真空态相互作用过程中辐射场的压缩和振幅平方压缩效应,讨论了两个二能级原子与光场的耦合常数的相对大小对它们的影响。 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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ZOU Anhua 《Chinese Journal of Lasers》1994,3(2):117-127
ThenonclassicalpropertiesofthesuperpositioninvolvingtwosqueezingcoherentstatesZOUAnhua(DepartmentofPhysics,ShengraoTeacbors'C... 相似文献
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In this paper the superpositions of two arbitrary coherent states |ψ〉 = α |β| + be^iψ |mβe^iδ〉 are constructed by using the superposition principle of quantum mechanics. The entropic squeezing effects of the quantum states are studied. The numerical results indicate that the amplitudes, the ratio between the amplitudes of two coherent states, the phase difference between the two components and the relative phase of the two coefficients play important roles in the squeezing effects of the position entropy and momentum entropy. 相似文献
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We consider the superpositions of spin coherent states and study the coherence properties and spin squeezing in these states. The spin squeezing is examined using a new version of spectroscopic squeezing criteria. The results show that the antibuching effect can be enhanced and spin squeezing can be generated in the superpositions of two spin coherent states. 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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构造了由多模真空态、多模泛函相干态、多模泛函相干态的相反态、多模复共轭泛函相干态和多模复共轭泛函相干态的相反态这五个宏观上完全可分辩的量子态线性叠加所构成的强度不等的非对称五态叠加多模泛函叠加态光场|Ψ(5)vas〉q.利用多模压缩态理论,首次研究了态|Ψ(5)vas〉q的广义非线性等幂奇数次高次振幅压缩特性.结果发现:在一定的条件下,态|Ψ(5)vas〉q可呈现任意次的广义非线性等幂次高次振幅压缩效应,其压缩程度、压缩深度和压缩幅度与压缩次数、腔模总数、态间叠加几率幅、各模光场的经典强度以及经典初始相位的空间分布函数等强烈地非线性相关联;特别是,在特定条件下,真空场的注入可以提高压缩程度. 相似文献
17.
W.S. Chung 《Fortschritte der Physik》2014,62(8):619-625
A new kind of spin coherent state called a Z3‐graded spin coherent state is constructed by using the complex solution of the equation q3 = 1. We explicitly find three kinds of Z3‐graded spin coherent states. The associated coherent property and spin squeezing are also examined. 相似文献
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To investigate the role of initial quantum coherence in work-probability distribution, it is necessary to consider an incomplete or partial measurement, in which the energy cannot be fully discriminated by the detector. In this paper, we use a harmonic oscillator with a coherent or squeezing state to realize this incomplete or partial measurement, and propose a unified framework of quantum work statistics for a closed system with an arbitrary initial state. We find that work is proportional to the change of the real part of the coherent state parameter, i.e., quantum work can be estimated by the coherent state parameter. The resulting work-probability distribution includes the initial quantum coherence, and can be reduced to the result of the traditional two projective energy measurement scheme(TPM) by squeezing the state of the harmonic oscillator. Our measurement scheme reveals the fundamental connections between measurement error and coherent work. By introducing a ‘coherent work-to-noise ratio', we find the optimal measurement error, which is determined by the energy difference between the superposed energy levels. As an application, we consider a driven two-level system and investigate the effects of driving velocity on work statistics. We find that only when the driving velocity matches the transition frequency of the system can initial quantum coherence play an important role. 相似文献
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We find that the coherent state projection operator representation of symplectic transformation constitutesa loyal group representation of symplectic group. The result of successively applying squeezing operators on numberstate can be easily derived. 相似文献