共查询到20条相似文献,搜索用时 62 毫秒
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为了研究非线性和叠加效应对量子态的影响,采用理论分析和数值计算相结合的方法,研究了一种新的量子态,即非线性圆态。分析了该态的平均光子数分布、亚泊松分布、压缩效应等非经典性质,同时计算了它的维格纳(Wigner)函数。数值模拟结果表明:随着Lamb-Dicke参数和叠加态数目的增大,非线性圆态的平均光子数增加,而由该态描述的光场的亚泊松分布和压缩效应受到减弱。表征非线性效应的Lamb-Dicke参数和叠加态数目对该态的非经典特性有明显的影响。 相似文献
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叠加qs相干态的非经典性质 总被引:1,自引:0,他引:1
构造了叠加qs相干态,并研究了它的压缩性质、反聚束效应等非经典性质.数值计算了叠加系数和形变参数q与s对非经典性质的影响.奇偶qs相干态的有关结果作为特例包含在本文的一般结论之中. 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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光子增加混沌场的退相干和非经典效应 总被引:1,自引:0,他引:1
将产生算符作用在混沌场上,构造了光子增加混沌场.利用有序算符内的积分技术和热纠缠态表象求解密度矩阵主方程的方法,研究了振幅衰减模型中光子增加混沌场的退相干和非经典效应.通过解振幅衰减模型中的密度算符的主方程,得到了初态为光子增加混沌场的密度算符的演化公式.计算了终态密度算符的P表示和Wigner函数,并数值计算了耗散对其P表示和Wigner函数的影响.结果表明:随耗散时间的增长,光子增加混沌场的非经典效应减弱.另一方面,随光子增加数的增加,其非经典效应也减弱. 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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将拉盖尔多项式算符作用在相干态上,构造了拉盖尔多项式算符激发相干态.利用有序算符积分技术,导出了它的归一化系数以及〈a^la^+m〉的计算表达式.采用数值计算方法,讨论了相干态相位角和平均光子数对它的非经典性质的影响.研究结果表明:一阶拉盖尔多项式算符激发相干态呈现出压缩效应、反聚束效应、亚泊松分布和Wigner函数负性等量子特性,并且相干态的相位角对它的量子特性有重要影响;另一方面,随相干态平均光子数增大,它的反聚束效应和亚泊松分布性质逐渐减弱,压缩效应和Wigner函数的负性却先增强,而后又逐渐减弱. 相似文献
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Nonclassicality and decoherence of coherent superposition operation of photon subtraction and photon addition on squeezed state 下载免费PDF全文
The statistical properties of m-coherent superposition operation (μa+νa+)m on the single-mode squeezed vacuum state (M-SSVS) and its decoherence in a thermal environment have been studied. Converting the M-SSVS to a squeezed Hermite polynomial excitation state, we obtain a compact expression for the normalization factor of M-SSVS, which is the Legendre polynomial of the squeezing parameter. We also derive the explicit expression of Wigner function (WF) of M-SSVS, and find the negative region of WF in phase space. The decoherence effect on this state is then discussed by deriving the time evolution of the WF. Using the negativity of WF, the loss of nonclassicality has been discussed. 相似文献
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Nonclassicality and decoherence of the coherent superposition operation of photon subtraction and addition on the squeezed state 下载免费PDF全文
The statistical properties of m-coherent superposition operation(μa + νa■)m on the single-mode squeezed vacuum state(M-SSVS) and its decoherence in a thermal environment are studied.Converting the M-SSVS to a squeezed Hermite polynomial excitation state,we obtain a compact expression for the normalization factor of M-SSVS,which is the Legendre polynomial of the squeezing parameter.We also derive the explicit expression of the Wigner function(WF) of the M-SSVS,and find the negative region of the WF in phase space.The decoherence effect on this state is then discussed by deriving the time evolution of the WF.Using the negativity of the WF,the loss of nonclassicality is then discussed. 相似文献
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By applying the bosonic creation operator to squeezed
vacuum states, this paper introduces a new kind of quantum states:
photon-added squeezed vacuum states. It also presents an
experimental approach to prepare these states, and investigates
their quantum statistical properties by the numerical method. The
results indicate that these states reveal some interesting
non-classical properties, such as anti-bunching effects,
squeezing effects and negativities of the relevant Wigner
functions. 相似文献
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The nonclassicality of the two-variable Hermite polynomial state is investigated. It is found that the two-variable Hermite polynomial state can be considered as a two-mode photon subtracted squeezed vacuum state. A compact expression for the Wigner function is also derived analytically by using the Weyl-ordered operator invariance under similar transformations. Especially, the nonclassicality is discussed in terms of the negativity of the Wigner function. Then violations of Bell’s inequality for the two-variable Hermite polynomial state are studied. 相似文献
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研究了由光子增减叠加操作作用于相干态而得量子态的非经典性及其在热环境中的退相干问题.通过解析导出了Mandel's Q参数、光子数分布、Wigner函数等,讨论其非经典性.研究表明一阶光子增减相干叠加相干态在相空间总是取负值,只要满足条件∣2z* +α-α*∣2<1.基于Wigner函数的演化积分公式,解析地推导出了在热环境中Wigner函数的简洁表达式.研究首次表明:如果κt<1/2ln[(2(η)+2)/(2(η)+1)]得以满足,一阶光子增减相干叠加相干态在相空间最小值点处Wigner函数分布总存在负部.此外,根据Wigner函数负部体积讨论了其非经典特性. 相似文献
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Comparison of nonclassicality between photon-added and photon-subtracted squeezed vacuum states 下载免费PDF全文
In this paper, we introduce photon-added and photon-subtracted squeezed vacuum state (PASV and PSSV) and obtain their normalized factors, which have the similar forms involved in Lengendre polynomials. Moreover, we give the compact expressions of Wigner function, which are related to single-variable Hermite polynomials. Especially, we compare their nonclassicality in terms of Mandel Q-factor and the negativity of Wigner function. 相似文献
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Li-juan Xu 《Optics Communications》2011,284(13):3335-3344
We investigate the nonclassicality of two-mode photon-added squeezed vacuum state (TPASV) and its decoherence in a thermal environment according to the sub-Poissonian statistics and the negative region of Wigner function (WF). Based on the fact that the TPASV can be seen as a squeezed Hermite polynomial excitation state, we further obtain a compact expression for the normalization factor of TPASV, i.e., a Jacobi polynomial of the squeezing parameter. We also derive the explicit expression of WF of TPASV and then the decoherence effect on this state is also discussed by deriving the time evolution of the WF and its negative region. 相似文献