介观电路中量子纠缠的经典对应

从量子力学诞生日起,它的经典对应(或类比)一直是物理学家关心的话题.本文以介观电路量子化的框架中,带有互感的两个介观电容-电感(LC)电路为例,首次讨论了量子纠缠的经典类比(或对应)问题.先用有序算符内的积分理论证明其互感是产生量子纠缠的源头;再推导出求解特征频率的公式,就发现它与一个经典系统的小振动频率的表达式有相似之处,该经典系统组成如下:两个墙壁各连一个相同的弹簧,两个弹簧之间接着一个滑动小车可以在光滑的桌面上运动,小车挂有一根单摆.用分析力学求此系统的小振动频率,发现与上述介观电路的特征频率形式类似,单摆的摆动会造成小车来回振动,摆、小车和弹簧的互相牵制效应反映了小车和摆的"纠缠".

有质弹簧缓慢腐蚀过程中的浸渐不变量及其电学推广

本文探讨并解出了有质弹簧缓慢腐蚀过程中的浸渐不变量,基于该模型推广到了平行板电容器中的电解质液体缓慢腐蚀情形下的浸渐不变量.求解过程中所包含的数学方法和物理思想能够为经典物理的量子化提供了可行的方向,此外该模型也可以简单地推广到磁介质退化情形下的浸渐不变量.

Quantum Fluctuation in Thermal Vacuum State for Mesoscopic LC Electric Circuit

We consider the quantization of LC(inductance-capacitance)circuit at a finite temperature T as any practical circuits always produce Joule heat except for superconductivity.It is shown that the quantum mechanical zeropoint fluctuations of both charge and current increase with upgoing T.Thermal Held dynamics is used in our discussion.

New Approach for Solving Master Equations in Quantum Optics and Quantum Statistics by Virtue of Thermo-Entangled State Representation

By introducing a fictitious mode to be a counterpart mode of the system mode under review we introduce the entangled state representation （η｜, which can arrange master equations of density operators p（t） in quantum statistics as state-vector evolution equations due to the elegant properties of （η｜. In this way many master equations （respectively describing damping oscillator, laser, phase sensitive, and phase diffusion processes with different initial density operators） can be concisely solved. Specially, for a damping process characteristic of the decay constant k we find that the matrix element of p（t） at time t in 〈η｜ representation is proportional to that of the initial po in the decayed entangled state （ηe^-kt｜ representation, accompanying with a Gaussian damping factor. Thus we have a new insight about the nature of the dissipative process. We also set up the so-called thermo-entangled state representation of density operators, ρ = f（d^2η/π）（η｜ρ〉D（η）, which is different from all the previous known representations.

Quantization and Squeezed State of Two L-C Circuits with Mutual-Inductance

It is pointed out that the quantum mechanical Hamiltonian of two L-C circuits with mutual-inductance is equivalent to a pair of harmonic oscillators with a kinetic coupling term.We then diagonalize the Hamiltonian.It is shown that instantaneously switching on the external sources may result in a two-mode squeezed state of the system,which actually arises from the effect of mutual-inductance.The quantum fluctuation for the case of l_(1)c_(1)=l_(2)c_(2 ) is analysed and it is found that the current fluctuation in the circuits increases with the increment of the mutual-inductance.

2020年东京奥运会延期的应对策略与现实启示

运用文献资料法等,研究2020年东京奥运会延期举办带来的多维影响及应对策略,并探究大型体育赛事面对突发重大公共卫生事件的路径选择。研究认为:随着国际奥委会和东京奥组委奥运会筹办工作的推进,已经及时有效地应对了东京奥运会延期举办带来的相关危机。在此基础上,建议整合组织资源,促使各方协力办赛;搭建公共平台,提升危机公关能力;共担延期成本,降至最低损失;团结国际社会力量,做好不可抗力因素应对预案。对大型体育赛事应对突发重大公共卫生事件的启示:高度重视风险评估,加大网络监控系统的建设力度,多部门协同联动形成防控合力,加强赛事工作人员业务培训并向公众普及公共卫生知识,加强与国际卫生组织的合作从而共享防控经验等。

Solving Energy Levels for SSH Hamiltonian Describing Peierls Phase Transition by Virtue of Invariant Eigen-operator Method

We show that the recently proposed invariant eigen-operator （IEO） method can be successfully applied to solving energy levels for SSH Hamiltonian describing Peierls phase transition. The electronic energy band of compound lattice is also studied by IEO method.

A New Kind of Two-Fold Integration Transformation in Phase Space and Its Uses in Weyl Ordering of Operators

We propose a new two-fold integration transformation in p-q phase space∫∫^∞-∞dpdq/π e^2i（p-x）（q-y）f（p,q）≡G（x,y）,which possesses some well-behaved transformation properties. We apply this transformation to the Weyl ordering of operators, especially those Q-P ordered and P-Q ordered operators.

New Approach for Calculating Tomograms of Quantum States by Virtue of the IWOP Technique

We show that for tomographic approach there exist two mutual conjugate quantum states [p,σ, τ） and [x,μ, ν） （named the intermediate coordinate-momentum representation）, and the two Radon transforms of the Wigner operator are just the pure-state density matrices [p）σ1τσ1τ （p｜ and （p）λ,ν,λ,ν,（x｜ respectively. As a result, the tomogram of quantum states can be considered as the module-square of the states＇ wave function in these two representations. Throughout the paper we fully employ the technique of integration within an ordered product of operators. In this way we establish a new convenient formalism of quantum tomogram.

Operator Fredholm Integration Equation in Intermediate Coordinate-Momentum Representation and Its Analogue to Thermo Conduction Equation

Using the technique of integration within an ordered product （IWOP） of operators we construct intermediate coordinate-momentum representation, with which we build a type of operator Fredholm integration equation that is an operator generalization of the solution of thermo conduction equation. Then we seach for the solution of operator Fredholm integration equations, which provides us with a new approach for deriving some operator identities.

Relationship Between Wave Function and Corresponding Wigner Function Studied in Entangled State Representation

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.

Damping Law of Photocount Distribution in a Dissipative Channel

For a dissipative channel governed by the master equation of the density operator describing the photon loss,we find that the photocount distribution formula at time𝑢can be related to the initial photocount distribution by replacing the efficiency of the detector𝜊ζwith𝜊ζe^(−2kt)𝜆𝑢,as if the quantum efficiencyζ𝜊of the detector becomes𝜊ζe^(−2kt)𝜆𝑢.This law greatly simplifies the theoretical study of the photocount distribution for quantum optical fields.

New Route to Deducing Integration Formulas by Virtue of the IWOP Techniqu~

We point out a new route to deducing integration formulas, i.e., using the technique of integration within an ordered product （IWOP） of operators we derive some new integration formulas, which seems concise. As a by-product, some new operator identities also appear.

Thermal Equilibrium Reached by Interaction Between Two Identical Systems

In this work we show that tending to thermal equilibrium in one system, at least in certain cases, is associated with the coherent dynamical evolution of this system in interaction with another identical system. The temperature varying effect with time is manifestly shown in our analyses.

Application of Eigenkets of Bosonic Creation Operator in Deriving Some New Formulas of Associated Laguerre Polynomials

Using the resolution of unity composed of bosonic creation operator＇s eigenkets and annihilation operator＇s un-normalized eigenket, which is a new quantum mechanical representation in contour integration form, we derive new contour integration expression of associated Laguerre polynomials L^ρm （｜z｜^2） and its generalized generating function formula. A series of recursive relations regarding to L^ρm （｜z｜^2） are also deduced in the context of the Fock representation by algebraic method.

Re-explanation of Weyl Quantization Scheme via Weyl Ordering Approach

We re-explain the Weyl quantization scheme by virtue of the technique of integration within Weyl orderedproduct of operators,i.e.,the Weyl correspondence rule can be reconstructed by classical functions' Fourier transfor-mation followed by an inverse Fourier transformation within Weyl ordering of operators.As an application of thisreconstruction,we derive the quantum operator coresponding to the angular spectrum amplitude of a spherical wave.

Convolution Theorem of Fractional Fourier Transformation Derived by Representation Transformation in Quantum Mechancis

Based on our previous paper (Commun.Theor.Phys.39 (2003) 417) we derive the convolution theoremof fractional Fourier transformation in the context of quantum mechanics,which seems a convenient and neat way.Generalization of this method to the complex fractional Fourier transformation case is also possible.

One- and Two-Mode Combination Squeezing Operator for Two Harmonic Oscillators with Coordinate-Momentum Coupling

By virtue of the technique of integration within an ordered product of operators, we derive the normal ordering expansion of a one- and two-mode combination squeezing operator for two harmonic oscillators with coordinate- momentum coupling. It turns out that this squeezing operator just diagonalizes the Hamiltonian H=p^21/2m1＋m1ω^21x^21/2＋p^222m2＋m2ω^22x^22/2-λx2p1 so its ground state is a one- and two-mode combination squeezed state. Quantum fluctuation in the ground state is calculated.

Pseudo-invariant Eigen-operator for Deriving Energy-Level Gap for Jaynes-Cummings Model

We extend the concept of invariant eigen-operator to pseudo-invariant eigen-operator case through analyzing the standard Jaynes-Cummings model. We find the pseudo-invariant eigen-operator in terms of supersymmetric generators of this model, which diretly leads to the energy-level gap for Jaynes Cummings Hamiltonian.

Photon Distribution of a Squeezed Chaotic State

We investigate the photon number distribution of squeezed chaotic field(SCF)(a mixed state),by converting the density operator of SCF into its normally ordered bivariate distribution form we find that it is a Legendre distribution.This is a remarkable result.