共查询到20条相似文献,搜索用时 203 毫秒
1.
利用热场动力学及相干热态表象理论,重构了有限温度下介观RLC电路的Wigner函数,研究了有限温度下介观RLC电路的量子涨落.借助于Weyl-Wigner理论讨论了有限温度下介观RLC电路Wigner函数的边缘分布,并进一步阐明了Wigner函数边缘分布统计平均的物理意义.结果表明: 有限温度下介观RLC电路中电荷和电流的量子涨落随着温度和电阻值的增加而增加,回路中的电荷和电流之间存在着压缩效应,这种量子效应是由于系统零点振动的涨落而引起的; 有限温度下介观RLC电路Wigner函数边缘分布的统计平均正好是储存在介观RLC电路中电容和电感上的能量. 相似文献
2.
利用热场动力学及相干热态表象理论,重构了有限温度下介观RLC电路的Wigner函数,研究了有限温度下介观RLC电路的量子涨落.借助于Weyl-Wigner理论讨论了有限温度下介观RLC电路Wigner函数的边缘分布,并进一步阐明了Wigner函数边缘分布统计平均的物理意义.结果表明:有限温度下介观RLC电路中电荷和电流的量子涨落随着温度和电阻值的增加而增加,回路中的电荷和电流之间存在着压缩效应,这种量子效应是由于系统零点振动的涨落而引起的;有限温度下介观RLC电路Wigner函数边缘分布的统计平均正好是储存在介观RLC电路中电容和电感上的能量. 相似文献
3.
相干态表象在量子相空间分布函数中的应用 总被引:1,自引:1,他引:0
利用相干态表象和IWOP技术导出了自由热态密度矩阵的正规乘积形式,进而根据相干态表象下的Wigner函数定义重构了自由热态和热相干态的Wigner函数.结果表明利用相干态表象下的Wigner函数定义和算符的正规乘积形式可以方便简捷重构一些量子态的Wigner函数. 相似文献
4.
Using the IWOP (integration within ordered product) technique, we derive a normally ordered form of the smoothed Wigner operator with which the smoothed Wigner function, that is specified only in the integral form in the literature, can be simplified. The application of the new form of the smoothed Wigner operator to the coherent state is also presented. 相似文献
5.
XU Xing-Lei LI Hong-Qi 《理论物理通讯》2008,49(6):1453-1456
By using the technique of integration within an ordered product (IWOP) of operator we derive Wigner function of density operator for negative binomial distribution of radiation field in the mixed state case, then we derive the Wigner function of squeezed number state, which yields negative binomial distribution by virtue of the entangled state representation and the entangled Wigner operator. 相似文献
6.
Using the coherent state representation of Wigner operator and the technique
of integration within an ordered product (IWOP) of operators, this
paper derives the Wigner
function for the Hermite polynomial state (HPS). The tomogram of
the HPS is calculated with the aid of newly introduced intermediate
coordinate-momentum representation in quantum optics. 相似文献
7.
Quantum fluctuations of mesoscopic damped double resonance RLC circuit with mutual capacitance--inductance coupling in thermal excitation state 总被引:7,自引:0,他引:7 下载免费PDF全文
Based on the scheme of damped harmonic oscillator quantization and
thermo-field dynamics (TFD), the quantization of mesoscopic damped
double resonance RLC circuit with mutual capacitance--inductance
coupling is proposed. The quantum fluctuations of charge and current
of each loop in a
squeezed vacuum state are studied in the thermal excitation case. It is shown
that the fluctuations not only depend on circuit inherent parameters,
but also rely on excitation quantum number and squeezing parameter.
Moreover, due to the finite environmental temperature and
damped resistance, the fluctuations increase with the temperature rising,
and decay with time. 相似文献
8.
Relationship Between Wave Function and Corresponding Wigner Function Studied in Entangled State Representation 总被引:1,自引:0,他引:1
XU Xing-Lei LI Hong-Qi FAN Hong-Yi 《理论物理通讯》2008,49(5):1159-1162
By using the explicit form of the entangled Wigner operator and the entangled state representation we derive the relationship between wave function and corresponding Wigner function for bipartite entangled systems. The technique of integration within an ordered product (IWOP) of operators is employed in our discussions. 相似文献
9.
《中国物理 B》2015,(12)
For the density operator(mixed state) describing squeezed chaotic light(SCL) we search for its thermal vacuum state(a pure state) in the real-fictitious space. Using the method of integration within ordered product(IWOP) of operators we find that it is a kind of one- and two-mode combinatorial squeezed state. Its application in evaluating the quantum fluctuation of photon number reveals: the stronger the squeezing is, the larger a fluctuation appears. The second-order degree of coherence of SCL is also deduced which shows that SCL is classic. The new thermal vacuum state also helps to derive the Wigner function of SCL. 相似文献
10.
Ying-Hua Ji 《Physics letters. A》2008,372(21):3874-3877
Taking into account the interactions between electrons and phonons, we study the dynamic behavior of a dissipative mesoscopic circuit for pure initial coherent state of phonon bath modes by virtue of the IWOP technique. It shows that if the bath modes are initially in coherent states, some phenomena like Brownian behavior will appear in mean charge and current of the mesoscopic circuit. The quantum fluctuations of charge and current are constant and irrelevant to the coupled coefficients between electrons and phonons. 相似文献
11.
12.
Zhi-Long Wan Hong-Yi Fan Heng-Mei Li Zhen Wang 《International Journal of Theoretical Physics》2017,56(10):3188-3201
For the density operator describing s?photon-subtracted squeezed chaotic light (PSSCL) we search for its thermo vacuum state (a pure state) in the real-fictitious space. We find that it reduces to a thermo vacuum state of squeezed chaotic light when s = 0, and to a thermo vacuum state of the optical negative binomial field when no squeezing. The new thermo vacuum state simplifies calculating photon number average, quantum fluctuation and Mandel’s Q parameter of PSSCL. Using the method of integration within ordered product (IWOP) of operators we also derive the normalization coefficient and explicitly analytical expressions of Wigner function for PSSCL. 相似文献
13.
Shuai Wang 《International Journal of Theoretical Physics》2009,48(5):1459-1465
For L-C circuit, a new quantized scheme has been proposed in the context of number-phase quantization. In this quantization
scheme, the number n of the electric charge q(q=en) is quantized as the charge number operator and the phase difference θ across the capacity is quantized as phase operator. Based on the scheme of number-phase quantization and the thermo field
dynamics (TFD), the quantum fluctuations of the charge number and phase difference of a mesoscopic L-C circuit in the thermal
vacuum state, the thermal coherent state and the thermal squeezed state have been studied. It is shown that these quantum
fluctuations of the charge number and phase difference are related to not only the parameters of circuit, the squeezing parameter,
but also the temperature in these quantum states. It is proven that the number-phase quantization scheme is very useful to
tackle with quantization of some mesoscopic electric circuits and the quantum effects. 相似文献
14.
Based on the Husimi operator in pure state form introduced by Fan et al., which is a squeezed coherent state projector, and the technique of integration within an ordered product (IWOP) of operators, as well as the entangled state representations, we obtain the Husimi functions of the excited squeezed vacuum states (ESVS) and two marginal distributions of the Husimi functions of the ESVS. 相似文献
15.
By analogy with the bosonic bipartite entangled state we construct fermionic entangled state with the Grassmann numbers. The Wigner operator in the fermionic entangled state representation is introduced, whose marginal distributions are understood in an entangled way. The technique of integration within an ordered product (IWOP) of Fermi operators is used in our discussion. 相似文献
16.
FAN Hong-Yi WANG Ji-Suo 《理论物理通讯》2007,48(2):245-248
By analogy with the bosonic bipartite entangled state we construct fermionic entangled state with the Grassmann numbers. The Wigner operator in the fermionic entangled state representation is introduced, whose marginal distributions are understood in an entangled way. The technique of integration within an ordered product (IWOP) of Fermi operators is used in our discussion. 相似文献
17.
Using the coherent state representation of Wigner operator and the
technique of integration within an ordered product (IWOP) of
operators, the Wigner functions of the even and odd binomial states
(EOBSs) are obtained. The physical meaning of the Wigner functions
for the EOBSs is given by means of their marginal distributions.
Moreover, the tomograms of the EOBSs are calculated by virtue of
intermediate coordinate-momentum representation in quantum optics. 相似文献
18.
Hong-yi Fan 《Annals of Physics》2007,322(4):866-885
Via the route of applying Newton-Leibniz integration rule to Dirac’s symbolic operators, we show that the density operator e−βH, where H is multi-mode quadratic interacting boson operators, is a mapping of symplectic transformation in the coherent state representation appearing in the form of non-symmetric ket-bra operator integration. By virtue of the technique of integration within an ordered product (IWOP) of operators, we deduce its normally ordered form which directly leads to the generalized partition function formula and the Wigner function. Some new representations, such as displacement-squeezing correlated squeezed coherent states, constructed by the IWOP technique, also bring convenience in deriving partition functions. 相似文献
19.
Based on thermo field dynamics (TFD) and using the thermo Wigner
operator in the thermo entangled state representation we derive the
Wigner function of number states at finite temperature (named thermo
number states). The figure of Wigner function shows that its shape
gets smoothed as the temperature rises, implying that the quantum
noise becomes larger. 相似文献