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1.
A perturbation method is used to study effective response of nonlinear Kerr composites, which are subject to the constitutive relation of electric displacement and electric field, Dα=εαE+xα|E|^2E. Under the external AG and DC electric field Eapp = Eα(1 + sinωt), the effective nonlinear responses and local potentials are induced by the cubic nonlinearity of Kerr materials at all harmonics. As an example in three dimensions, we have investigated this kind of nonlinear composites with spherical inclusions embedded in a host. At all harmonic frequencies, the potentials in inclusion and host regions are derived. Furthermore, the formulae of the effective linear and nonlinear responses are given in the dilute Iimit.  相似文献   

2.
A perturbative approach is used to study the AC response of nonlinear compostie media,which obey a current-field relation of the form J=σE χ|E|^2E with comp[onents having nonlinear response at finite frequencies.For a sinusoidal applied field,we extend the local potential in terms of sinusoidal components at fundamental frequency and high-order harmonic frequencies to treat the nonlinear comosites.For nonlinear composite media with a low concentrations of spherical inclusions,we give the formulae of the nonlinear effective AC susceptibility χ3ω at the third harmonic frequency.  相似文献   

3.
By means of a variational approach, we study the effective response of strongly nonlinear composite media with a low concentration of cylindrical or coated cylindrical inclusions. In an attempt to consider the influence of nonlinear order to effective nonlinear response, we assume that every constituent of the composites obeys a current-field relation of the form J =Χ|E|βE. In dilute limit, we have presented some numerical results for the case of the third-order nonlinearity (i.e.β= 2) and the fifth-order nonlinearity (i.e.β= 4), and compared the effective response of the third-order nonlinearity with that of the fifth-order nonlinearity, some conclusions are drawn.  相似文献   

4.
赵庆凯  陈小刚  崔继峰 《物理学报》2013,62(10):107201-107201
利用同伦分析方法, 研究了一类由柱形杂质随机嵌入基质所形成的、电场和电流密度满足J = σ E + χ |E|2E + η|E|4E 形式本构关系的高阶弱非线性复合介质在外加直流电场作用下的电势分布问题. 首先利用模函数展开法, 将本构方程及边界条件化成了一系列非线性常微分方程的边值问题; 再利用同伦分析方法进行求解, 给出了电势在基质和杂质区域的渐近解析解. 关键词: 高阶弱非线性复合介质 模函数展开法 同伦分析方法 电势分布  相似文献   

5.
Perfect quantum state mirroring in a chain of N spins is defined as the condition in which the state |iof the chain is swapped into the state |N-i within a time evolution interval τ.Such a phenomenon is an interesting way of transfering entanglement.An expressions for the perfect mirroring of a single qubit contained in a spin chain were proposed in the past.We exploit such an expressions for calculating the evolution times in chains of both two and three spins.In the case of a chain of two qubits,we derive conditions under which the associated four Bell states diagonalize the Hamiltonian.It is found that for the two Bell states |Φ+and|Φ-,perfect mirroring does not occur(i.e.entanglement is not preserved under swapping).On the other hand,perfect single qubit mirror effect(entanglement preservation) indeed occurs for the other two Bell states |Ψ+and|Ψ- which are mapped into |Φ+and|Φ-respectively.For the case of a chain of three qubits,the effects of a perfect single qubit mirroring on a set of four maximally entangled three qubit states ψ1,ψ2,χ1,and χ2 are studied.Due to the fact that quantum mirroring preserves maximal entanglement,the states ψ1 and ψ2 are not altered.However,quantum mirroring changes the states χ1 and χ2 only if we apply perfect quantum state mirroring in the site a=1 of the three qubits spin chain.The above constrains the preservation of maximal entanglement under qubit mirroring of such a state.Due to the fact that swapping has already been experimentally tested,a posible experimental implementations of single qubit mirroring is possible.  相似文献   

6.
By using the perturbation method,effective nonlinear direct current(DC) and alternating current(AC) responses of nonlinear composites with spherical coated inclusions randomly embedded in a host medium are studied under the action of an external electric field E a = E 0 + E 1 sin ωt + E 3 sin 3ωt with different amplitudes and frequencies.The local potentials of composites at all harmonics are given in the inclusion particles and the host regions.All effective nonlinear responses to composites and the relationship between the effective nonlinear responses at all harmonics are also deduced for the spherical coated inclusions in a dilute limit.  相似文献   

7.
A single-spin transition critical dynamics is used to investigate the three-dimensional kinetic Ising model on an anisotropic cubic lattice,We first derive the fundamental dynamical equations.and then linearize them by a cutoff approximation.We obtain the approximate solutions of the local magnetization and equal-time pair correlation function approximation.We obtain the approximate solutions of the local magnetization and equal-time pair correlation function in zero field.In which the axial-decoupling terms γ1γ2,γ2γ3and γ1γ3as higher infinitesimal quantity are ignored,where γα=tanh(2k0633)=tanh(2Jα/kβT)(α=1,2,3,)We think that it is reasonable as the temperature of the system is very high.The result of what we obtain in this paper can go back to the one-dimensional Glauber‘s theory as long as k2=k3=0.  相似文献   

8.
By the concept of effective boson numbers, systematics of E21+E41+E61+, R=E21+/E41, B(E2, 01+→21+) and Q0 for even-even nuclei with A≥70 are presented. New features of energy spectra are noticed and an intuitive understanding is given.  相似文献   

9.
Based on the technique of integral within an ordered product of nonlinear bosonic operators, we construct a new kind of tripartite nonlinear entangled state |α,γ〉λ in 3-mode Fock space, which can make up a complete set. We also simply discuss its properties and application.  相似文献   

10.
The structural and spectroscopic properties of Na2O-Al2O3-SiO2-xP2O5 glasses(x = 0 to 7 mol%) are investigated.Both Raman and IR spectra reveal that discrete phosphate species([PO4]-3,[PO3O1/2]-2) with low polymerization degree can be formed in the silicate glass.These phosphate structures scavenge non-bridging oxygen ions and cations from the silicate network,resulting in an increase of the glass transition temperature.According to the Judd-Ofelt intensity parameters(Ω246) of Er3+.the asymmetry of local environment around Er3+ becomes higher,and the bond covalency between Er3+ and O2-decreases after P2O5 is introduced.In the emission spectra,photo-luminescence intensity increases with increasing P2O5 concentration and the spectra are inhornogeneously broadened,revealing that the ligand electric field around Er3+ is dramatically changed,and the glass matrix becomes disordered.  相似文献   

11.
The cross sections of Ω+Ω→(ΩΩ)Jπ=0++X are studied by using an effective Hamiltonian method. The results are σΩ+Ω→(ΩΩ)0+=0.03~0.16×10-29 cm2 for pΩ=100~400 MeV, and the cross sections of η production are about 10-28 cm2 for pΩ > 880 MeV.  相似文献   

12.
The Gaussian wave functional method is applied to a boson system with an array of local nonlinear potentials cos[βφ(nR)] to study the phase diagram of its ground state. The stable ground state is determined by the renormalized mass μ which is a function of the parameter γ=β2/4φ, the strength of potential α and the potential concentration c. In different cases γ<γ1, γ1<γ<γ2 and γ>γ2, μ can have different multiplicities, the phase diagram in parameter space is thus depicted. The value γ=γ1 depends on the concentration c, for c→0, it coincides with that of the single impurity model; while γ2=2 coincides with the conclusion of the continuous model.  相似文献   

13.
丁霞  贾艳霞  魏恩泊 《中国物理 B》2012,21(5):57202-057202
The perturbation method is used to study the localization of electric field distribution and the effective nonlinear response of graded composites under an external alternating-current (AC) and direct-current (DC) electric field Eapp = E0 (1+sin ωt). The dielectric profile of the cylindrical inclusions is modeled by function εi (r) = Ck rk (r ≤ a), where r is the radius of the cylindrical inclusion, and Ck, k, a are parameters. In the dilute limit, the local potentials and the effective nonlinear responses at all harmonics are derived. Meanwhile, the general effective nonlinear responses are also derived and compared with the effective nonlinear responses at harmonics under the AC and DC external field. It is found that the effective nonlinear AC and DC responses at harmonics can be calculated by those of the general effective nonlinear of the graded composites under the external DC electric field. Moreover, the obtained local electrical fields show that the electrical field distribution in the cylindrical inclusions is controllable, and the maximum of the electric field inside the cylinder is at its center.  相似文献   

14.
This paper uses the perturbation method to study effective response of nonlinear cylindrical coated composites. Under the external AC and DC electric field Ea(1 + sinωt), the local potentials of composites at all harmonic frequencies are induced. An effective nonlinear response to composite is given for the cylindrical coated inclusions in the dilute limit.  相似文献   

15.
The cross sections of Ω Ξ→(ΩΩ)J^π=0 K(K^*) and Ω Ω→(ΩΩ)J^π=0 η‘(φ) are studied by using an effective Hamiltonian method.For the two pseudo-scalar meson production processes,the cross sections are still in the order of several μbs,but for the two vector meson production processes,the cross sections are about 10 times larger than those in pseudo-scalar meson production case when the coupling constants of vector meson fields are fixed according to gNNρ and fNNρ in NN scattering and the SU(3) relation.  相似文献   

16.
The effective dielectric response of linear composites containing graded material is investigated under an applied electric field E0. For the cylindrical inclusion with gradient dielectric function, εi(r)=b+cr, randomly embedded in a host with dielectric constant εm, we have obtained the exact solution of local electric potential of the composite media regions, which obeys a linear constitutive relation D=εE, using hypergeometric function. In dilute limit, we have derived the effective dielectric response of the linear composite media. Furthermore, for larger volume fraction, the formulas of effective dielectric response of the graded composite media are given.  相似文献   

17.
本文用X射线粉末法测定了Li2K(IO3)3与Li2NH4(IO3)3的晶体结构和原子参数。发现Li3K(IO3)3,Li2NH4(IO3)3与Li2Rb(IO3)3同晶型,属单斜晶系,空间群为P21/α,每个单胞含有四个化合式量。室温的点阵常数分别为α=11.198?,b=11.046?,c=8.254?,β=111.53°,及α=11.327?,b=11.078?,c=8.341?,β=111.87°。讨论了二元化合物的形成与离子半径的关系。 关键词:  相似文献   

18.
The rate for the conversion of the gluon into a color octet quark pair which subsequently forms a multiquark state with another quark pair or a gluon is discussed. The static potential in a [(QQ)8(qq)8,1] state where Q=c,b and q=u, d is studied in the MIT bag model. It is shown that the repulsive Coulomb force between Q and Q is dominant at small QQ separations, which would significantly suppress the QQ wave function at the origin. For the charm quark (Q=c) the ratio of |Ψ(O)|2 for the ordinary (QQ)1 to that for the(QQ)8 in the [(QQ)8(qq)8,1] state is estinated to be 2-5. Therefore the assumption |Ψ8(O)|2=|Ψ1(O)|2 would lead to an overestimation for the rate of g*→QQ and it is necessary to take the suppression effect of the repulsive Coulomb force into consideration.  相似文献   

19.
通过高温固相法制得双峰可调节本征半导体发光BaZn2(BO32:Eu3+荧光粉,此类荧光粉在300~400 nm的紫外波段有很强的吸收。在375 nm的紫外光激发下,该荧光粉产生了两个宽带的发射峰,分别位于550 nm和615 nm处。并且,在395 nm的紫光激发下,荧光粉会由于Eu3+离子的5D07F2电偶极跃迁产生一个位于615 nm的强宽发射峰,这表明Eu3+离子占据了反演对称中心的位置,取代了BaZn2(BO32中部分的Ba2+离子。当Eu3+的摩尔分数达到10%时,发生浓度猝灭。在不同浓度的Eu3+离子的掺杂下,BaZn2(BO32:Eu3+荧光粉的发光从黄色延伸到红色,实现了荧光粉的色度可调。  相似文献   

20.
许亮  魏斌  夏勇  邓联忠  印建平 《中国物理 B》2017,26(3):33702-033702
Recently, there have been great interest and advancement in the field of laser cooling and magneto-optical trapping of molecules. The rich internal structure of molecules naturally lends themselves to extensive and exciting applications. In this paper, the radical~(138)Ba~(19) F, as a promising candidate for laser cooling and magneto-optical trapping, is discussed in detail.The highly diagonal Franck–Condon factors between the X~2Σ~+_(1/2)and A~2Π_(1/2) states are first confirmed with three different methods. Afterwards, with the effective Hamiltonian approach and irreducible tensor theory, the hyperfine structure of the X~2Σ~+_(1/2)state is calculated accurately. A scheme for laser cooling is given clearly. Besides, the Zeeman effects of the upper(A~2Π_(1/2)) and lower(X~2Σ~+_(1/2)) levels are also studied, and their respective g factors are obtained under a weak magnetic field.Its large g factor of the upper state A~2Π_(1/2) is advantageous for magneto-optical trapping. Finally, by studying Stark effect of Ba F in the X~2Σ~+_(1/2), we investigate the dependence of the internal effective electric field on the applied electric field. It is suggested that such a laser-cooled Ba F is also a promising candidate for precision measurement of electron electric dipole moment.  相似文献   

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