共查询到20条相似文献,搜索用时 31 毫秒
1.
减光子压缩真空态的反群聚效应 总被引:4,自引:2,他引:2
利用玻色产生算符的逆算符及玻色湮没算符作用于压缩真空态来构造减光子压缩真空态,并通过计算减光子压缩真空态的二阶关联函数来讨论它们的光子反群聚性质。数值计算结果表明,在两种情况下所得到的减光子压缩真空态当湮没光子数k为奇数时均呈现出群聚效应,而当k为偶数时呈现反群聚效应。所呈现的反群聚效应对应的压缩参量η的取值区间与湮没的光子数k有关,在玻色产生箅符的逆算符的作用下随着k的增加,反群聚效应对应的压缩参量η的取值区间扩大,在玻色湮没算符作用下则相反。同时,作出二阶关联函数随压缩参量η变化的曲线来描述减光子压缩真空态所呈现的反群聚效应的变化特性。 相似文献
2.
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
3.
《Physics letters. A》1999,259(1):7-14
In a recent paper, a new λ-dependent squeezed states was proposed [J. Beckers, N. Debergh and F.H. Szafraniec, Phys. Lett. A 243 (1998) 256–260] in which the usual Fock-space creation operator has been modified by introducing a simple translational term. In this paper, we generalize this approach by adding a new term proportional to the creation operator using exponential quadratic operators. 相似文献
4.
量子体系中的时域压缩-频域展宽正、逆效应及其非经典性 总被引:25,自引:17,他引:8
本文利用全量子理论,对连续能谱量子体系和分立能谱量子体系中的时域压缩-频域展宽以及频域压缩-时域展宽效应进行了详细研究.在文献17构造时间算符的基础上给出频率算符ω∧的定义,根据时间算符t∧与频率算符ω∧之间的对易关系并利用Cauchy-Schwartz不等式导出t∧和ω∧所满足的测不准关系式.给出时域压缩和频域压缩的定义,并对时域/频域上的最小测不准态、压缩最小测不准态和压缩态等进行了详细讨论,指出了时域压缩和频域压缩的非经典性质.给出时域上的拟量子产生算符τ∧+(t)、拟量子湮没算符τ∧(t)和拟量子数算符N∧τ(t)的定义,首次建立了时域量子化的形式理论,并由此进一步提出了时域量子化的基本观点. 相似文献
5.
We construct a new type of photon-added squeezed coherent state generated by repeatedly operating the bosonic creation operator on a new type of squeezed coherent state [Fan H Y and Xiao M 1996 Phys. Lett. A 220 81]. We find that its normalization factor is related to single-variable Hermite polynomials. Furthermore, we investigate its statistical properties, such as Mandel’s Q parameter, photon-number distribution, and Wigner function. The nonclassicality is displayed in terms of the intense oscillation of photon-number distribution and the negativity of the Wigner function. 相似文献
6.
In this paper, we introduce the squeezed displaced Wigner operator. We proved that the squeezed displaced Wigner operator can bring more convenience to calculate the Wigner functions of squeezed states. Finally, we give some new applications of such squeezed displaced Wigner operator. 相似文献
7.
Deformed photon-added entangled squeezed vacuum and one-photon states: Entanglement,polarization, and nonclassical properties
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In this paper, after a brief review on the entangled squeezed states, we produce a new class of the continuous-variabletype entangled states, namely, deformed photon-added entangled squeezed states. These states are obtained via the iterated action of the f-deformed creation operator A = f(n)aon the entangled squeezed states. In the continuation, by studying the criteria such as the degree of entanglement, quantum polarization as well as sub-Poissonian photon statistics, the twomode correlation function, one-mode and two-mode squeezing, we investigate the nonclassical behaviors of the introduced states in detail by choosing a particular f-deformation function. It is revealed that the above-mentioned physical properties can be affected and so may be tuned by justifying the excitation number, after choosing a nonlinearity function. Finally, to generate the introduced states, we propose a theoretical scheme using the nonlinear Jaynes–Cummings model. 相似文献
8.
根据温度效应与动力学压缩效应在数学处理上的相似性,将热化算符与压缩算符推广为一般的广义热化算符,通常的双模压缩态成为实空间的热场态,其中任何一个模的光子分布都具有经典的Bose-Einstein热场分布的特点(单模纯量子热化效应)。 相似文献
9.
研究了有压缩和驱动项的含时谐振子系统的时间演化.通过适当选取厄密不变量,得到含时谐振子系统的量子态时间演化的封闭解及该系统的时间演化算符,给出产生压缩态的条件,得出驱动项不影响系统压缩态的结论.
关键词: 相似文献
10.
两模在单双模组合压缩真空态中同等程度地被压缩 总被引:2,自引:2,他引:0
从SG相位算符的正规编序形式出发,我们得到了双模的SG相位算符在单双模组合压缩真空态中无相位差.这说明,在单-双模组合压缩真空态中两模同等程度地被压缩.这对探索新的压缩机制具有一定的启发作用. 相似文献
11.
12.
《Physica A》1995,215(4):556-576
The master equation for the reduced atomic density operator for the Dicke model (Na 2-level atoms on the same single site) interacting with a broad-band squeezed vacuum state field is derived using operator reaction field theory. The analysis through reaction field theory is presented first of all for the normal vacuum and then for the squeezed vacuum, both within the Markov and Born approximations. In the case of the squeezed vacuum field a statistical decorrelation between matter and field variables is also necessarily adopted in order to close the system of equations: this is also the case for the broad-band black-body field, and the theory contrasts with that which employs projection operator techniques and uses weak coupling. Models involving a both axially symmetrical and wholly isotropic distribution of the squeezed vacuum modes are compared. 相似文献
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15.
CHEN Chang-Yong 《理论物理通讯》2011,56(1):91-95
We give the brief review on the related definition of the geometric phase independent of specific physical system based on the displacement opreator and
the sqeezed operator, then show how the displacement operator and the squeezed operator can induce the general geometric phase. By means of the displacement operator and the squeezed operator concerning the circuit cavity mode state along a closed path in the phase space, we discuss specifically how to implement a two-qubit geometric phase gate in circuit quantum electrodynamics with both single photon interaction and two-photon interaction between the superconducting qubits and the circuit cavity modes. The experimental feasibility is discussed in detail. 相似文献
16.
YANGWei-Min JINGSi-Cong 《理论物理通讯》2001,35(3):283-287
By virtue of the parabose squeezed operator,propagator of a parabose parametric amplifier,explicit forms of parabose squeezed number states and normalization factors of excitation states on a parabose squeezed vacuum state are calculated,which generalize the relevant results from ordinary Bose statistics to the parabose case. 相似文献
17.
We find that a squeezing transformation can efficiently simplify the density operator equation of field damping in a squeezed
bath. Then the entangled state representation is introduced to solve the simplified equation and the time evolution of density
operator, which turns out to be a mixed coherent squeezed state.
Work supported by the President Foundation of Chinese Academy of Science and Specialized research fund for the doctorial progress
of Higher Education (SRFDP). 相似文献
18.
本文利用格子液体方法对文献中给出的V型三能级原子玻色-爱因斯坦凝聚体与双模压缩相干态光场相互作用系统的哈密顿量进行分析,发现文献中对原子间相互作用部分的处理有不合理之处,从而对该哈密顿量作出了改进并研究了V型三能级原子双模光场系统中光场压缩性质.结果表明:光场两正交分量交替呈现周期性压缩现象,其压缩深度与光场初始压缩因子密切相关,而压缩时间与双模光场的频率有关.
关键词:
玻色-爱因斯坦凝聚
V型三能级原子
压缩相干态
双模压缩态光场 相似文献
19.
FAN Hong-Yi WANG Hui 《理论物理通讯》2001,(10)
We discuss the entanglement swapping of two pairs of displaced two-mode squeezed states and find that the squeezing parameter of the outcoming squeezed state is less than that of the originM squeezed states. The calculation is greatly simplified by virtue of the natural expression of the two-mode squeezing operator in EPR eigenstate representation. A protocol for such entanglement swapping is proposed.`` 相似文献
20.
P. K. Suresh 《International Journal of Theoretical Physics》2004,43(2):425-436
A thermal squeezed state representation of inflaton is constructed for a flat Friedmann–Robertson–Walker (FRW) background metric and the phenomenon of particle creation is examined during the oscillatory phase of inflaton, in the semiclassical theory of gravity. An approximate solution to the semiclassical Einstein equation is obtained in thermal squeezed state formalism perturbatively and is found obey the same power-law expansion as that of classical Einstein equation. In addition to that the solution shows oscillatory in nature except on a particular condition. It is also noted that, the coherently oscillating nonclassical inflaton, in thermal squeezed vacuum state, thermal squeezed state, and thermal coherent state, suffers particle production and the created particles exhibit oscillatory behavior. The present study can account for the postinflation particle creation due to thermal and quantum effects of inflation in a flat FRW universe. 相似文献