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1.
In this paper, we give the most general duality gates, or generalized quantum gates in duality quantum computers. Here we show by explicit construction that a n-bit duality quantum computer with d slits can be simulated perfectly with an ordinary quantum computer with n qubits and one auxiliary qudit. Using this model, we give the most general form of duality gates which is of the form ∑i=0^d-1piUi,and the pi 's are complex numbers with module less or equal to 1 and constrained by|∑iPi|≤1.  相似文献   

2.
Bianchi type I string dust cosmological models in the presence and absence of magnetic field in the frame work of Lyra geometry are investigated. To get the deterministic model of the universe, we assume that the eigenvalue (σ11 ) of shear tensor (σi j ) is proportional to expansion (θ ). This leads to A =(BC)n, where A, B, C are metric potentials and n is a constant. To discuss the results in terms of cosmic time t, we have considered n = 1. The physical and geometrical aspects of the models and singularities in the models are also discussed.  相似文献   

3.
We examine the contribution of electromagnetic field to the atomic spin, by adopting two different, both gauge invariant definitions of the electromagnetic angular momentum: \vec{J}I ≡ ∫d3 x ε0 \vec{r} X (\vec{E} X \vec{B}) and \vec{J}II ≡ ∫d3 x ( ε0 \vec{E} X \vec{A}^\bot + ε0 Ei \vec{r} X \vec{\nabla }A^{\bot}i ). Notably, at the classical level, \vec{J}II gives an exactly null result while \vec{J}I gives a finite value. This suggests that \vec{J}II leads to a simpler and more reasonable picture of the atomic spin, therefore qualifies as a more appropriate definition of the electromagnetic angular momentum. Our observation gives important hint on the delicate issue of gluon contribution to the nucleon spin.  相似文献   

4.
We investigate statistical properties of multispecies competition ecosystems subjected to both symmetric and asymmetric dichotomous noises. The expression of the stationary probability distribution function (SPDF) is analytically derived by means of mean-field approximation, and verified bystochastic simulations. The results indicate that: (i) A noiseamplitude (a0), a noise autocorrelation time (τ0) and a noise symmetry parameter (k) all can affect the SPDF; (ii) There is an optimal τ0, which makes the mean value of population density be maximal, near which a transition takes place, i.e., the stationary mean value of species density (st) suddenly falls to a lower constant; (iii) As k decreases, the maximum of< x>st and the optimal τ0 increase. The parameter planes of τ0-a02 and τ0-k for the transition are plotted.  相似文献   

5.
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 ρ(t) in quantum statisticsas 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 thedecay constant κ we find that the matrix element of ρ (t) at time t in <η| representation is proportional to that of the initial ρ0 in the decayed entangled state <ηe-κt| 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=∫(d2η /π)< η | ρ> D(η), which is different from all the previous known epresentations.  相似文献   

6.
In this paper, we calculate the branching ratios for B+ → Ds+η, B+ → Ds+η ', B+ → Ds*+η, and B+ → Ds*+η ' decays by employing the perturbative QCD (pQCD) factorization approach. Under the two kinds of η-η' mixingschemes, the quark-flavor mixing scheme and the singlet-octet mixingscheme, we find that the calculated branching ratios agree well withthe currently available experimental upper limits. We also consider the so called ``fD_s puzzle', by using two groups of parameters about the D(*)s meson decay constants, that are fD_s=241 MeV, fD^*_s=272 MeV and fD_s=274 MeV, fD^*_s=312 MeV, to calculate the branching ratios for theconsidered decays. We find that the results change 30% by usingthese two different kinds of paramters.  相似文献   

7.
Adding a U(1) symmetry breaking term V1/2 a(λ1a0+λ*1a&#8224;0)+V1/22b0*2b&#8224;0) to Bogoliubov's truncated Hamiltonian HB for a weakly interacting coupled Bose system, by using the mean-field approximation rather than the c-number approximation, we find that, via a Feshbach resonance at zero temperature, the states of the coupled Bose system are generalized SU(1,1) × SU(1,1) coherent states. The Bose-Einsteincondensation occurs in response to the spontaneous U(1) symmetry breaking.  相似文献   

8.
In order to study the collisional quantum interference (CQI) on rotational energy transfer in atom-diatom system, we have studied the relation of the integral interference angle and differential interference angle in Na+Na2 (A1Σ+u, v=8∽b3Π0u, v=14) collision system. In this paper, based on the first-Born approximation of time-dependent perturbation theory and takinginto accounts the anisotropic effect of Lennard-Jones interaction potentials,we present a theoretical model of collisional quantum interference inintramolecular rotational energy transfer, and a relationship betweendifferential and integral interference angles.  相似文献   

9.
As well known, if the Higgs boson were not observed at LHC, the technicolor model would be the most favorable candidate responsible for the symmetry breaking. To overcome some defects in the previous model, some extended versions have been proposed. In the TC2 model typical signature is existence of heavy HTC and technipion Π. A direct proof of validity of the model is to produce them at accelerator. Thus we study the production rates of e+ e- → HTCΠ0 and e+ e- → Π+ Π- at ILC in the topcolor-assisted technicolor (TC2) model. In fact, there is a flood of models belonging to new physics, which can result in products withcharacteristics similar to HTC+Π of the TC2 model. Therefore to distinguish this model from others one may need to investigate some details by calculating the cross section to NLO. We indeed find that the NLO corrections are significant, namely the ratio δ ≡ (σNLO- σLO)/σLO in e+ e- → HTC Π0 exceeds 100% within a plausible parameter space.  相似文献   

10.
Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of normal metal/dx2-y2+idxy mixed wave superconductor graphene junctions. It is found that the conductance spectra vary strongly with the orientation of the gap and the amplitude ratio (Δ10) of two components for dx2-y2+idxy mixed wave. The zero bias conductance isnearly 2 and the conductance peak vanishes in doped graphene forα=0 and Δ10=1. The conductance increases with increasing the amplitude ratio of two components for α=π/4 and Δ10=1. The ZBCP becomesobservable wide with 1F/Δ0<100 for α=π/4 and Δ10=1. This property is different from that in normal metal/dx2-y2 wave superconductor graphenejunctions.  相似文献   

11.
采用喷雾热解法制备红色荧光粉LiEu(SiO2)1/6W2O8。研究了反应温度、前驱体溶液浓度、载气流速对实验结果的影响。通过扫描电镜、X射线衍射、激发和发射光谱对所制样品进行了研究,发现样品颗粒呈实心类球形、结晶度好、表面光滑、发光强度较高、粒径平均1.5μm左右且分布较窄。该类荧光粉激发主峰位于396nm,发射主峰位于615nm。LiEu(SiO2)1/6W2O8发光的色坐标为:x=0.667 9,y=0.3310,与NTSC的红色标准基本一致,该荧光粉色纯度非常高,适用于制造紫光芯片激发的白光LED。用喷雾热解法制备红色荧光粉LiEu(SiO2)1/6W2O8的研究尚未见报道。  相似文献   

12.
Using the bosonic coherent state representation and the Schwinger bosonic operator realization of angular momentum we find the formula for the quantum Hamiltonian H =iaiUijUjl a1 for SU(2) rotation U, in this way we further specify the angular velocity w, iUU = (1/2)σ·ω, where σ is the Pauli matrix. Though the spin as a quantum observable has no classical correspondence, we may still mimic it as a rigid body rotation characterized by 3 Euler angles, and calculate its Pseudo-classical rotational partition function of spin one-half.  相似文献   

13.
在氯仿和乙酸乙酯溶液中合成了1,6-二[(2′-苄胺甲酰基)苯甲氧基]己烷(L)的铕和铽的配合物,及其与La(Ⅲ)、Gd(Ⅲ)、Y(Ⅲ)的混合配合物。元素分析数据表明单—稀土硝酸盐与配体形成的是2:3型的配合物;通过红外光谱表征,混合配合物和单一配合物具有相似的配位结构。紫外光谱的数据表明,掺杂数量相同的其他离子会干扰Eu和Tb配合物对紫外光的吸收。对混合配合物的荧光进行了详细的研究,结果表明:La(Ⅲ)、Gd(Ⅲ)、Y(Ⅲ)对铕和铽的发光有显著的增强作用,但对其发射峰位的影响不大,三种离子中Gd3+的增强作用最大,且掺杂量对荧光增强作用也有影响。  相似文献   

14.
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.  相似文献   

15.
The molecular-based magnetic materials AFeIIFeIII (C2O4)3 have ahoneycomb structure in which FeIII (S=2) and FeIII (S=5/2) occupy sites alternately. They can be described as mixed spin-2 and spin-5/2 Ising model with ferrimagnetic interlayer coupling. The influences of the transversefield on the internal energy and the specific heat of the molecular-based magnetic system have been studied numerically by using the effective-field theory with self-spin correlations and the differential operator technique.  相似文献   

16.
By applying the Fourier slice theorem, Sθ(λ) =∫_{-\infty }^{\infty }Pθ(t)e-iλt=F(λcosθ,λsinθ), where Pθ(t) is a projection of f( x,p) =∫∫_{-\infty}^{\infty }F( u,v) ei(ux+vp)ldudv along lines of constant, to the Wigner operator we are naturally led to projection operator (pure state), which results in a new complete epresentation. The Weyl orderimg formalism of the Wigner operator is used in the derivation.  相似文献   

17.
The PD(X^3∑^-) interaction potential is constructed using the CCSD(T) theory and the basis set, augcc-pV5Z. Using this potential, the spectroscopic parameters are accurately determined. The present Do, De, Re, ωe, ωeχe, αe, and Be are of 3.056 99 eV, 3.161 75 eV, 0.142 39 nm, 1701.558 cm^-1, 23.6583 cm^-1, 0.085 99 cm^-1, and 4.3963 cm^-1, respectively, which almost perfectly conform with the measurements. A total of 26 vibrational states is predicted when J = 0 by solving the radial Sehrodinger equation of nuclear motion. The complete vibrational levels, classical turning points, initial rotation and centrifugal distortion constants when J = 0 are reported for the first time, which favorably agree with the experiments. The total and various partial-wave cross sections are calculated for the elastic impact between two ground-state P and D atoms at 1.0 × 10^-12 - 1.0 × 10^-4 a.u. when they approach each other along the PD(X^3∑^-) potential. No shape resonances exist in the total elastic cross sections, though the peaks can be found for each partial wave until l=6. The shape of the total elastic cross sections is dominated by the s partial wave at very low temperatures. Due to the weakness of the shape resonances of each partial wave, they are all passed into oblivion by the strong total elastic cross sections.  相似文献   

18.
We propose to use a set of averaged entropies, the multiple entropymeasures (MEMS), to partially quantify quantum entanglement ofmultipartite quantum state. The MEMS is vector-like with m=[N/2]components: [S1, S2,..., Sm], and the $i$-th component Si is the geometric mean of i-qubits partial entropy of the system. The Si measures how strong an arbitrary i qubits from the system are correlated with the rest of the system. It satisfies the conditions for a good entanglement measure. We have analyzed the entanglement properties of the GHZ-state, the W-states, and cluster-states under MEMS.  相似文献   

19.
靳辉  滕枫  孟宪国  侯延冰  徐征 《发光学报》2003,24(6):577-582
研究了聚合物PVK与TiO2分层光电导器件的电荷传输特性,分别比较了两种器件:器件S1(ITO/TiO2/PVK/Al)和器件S2(ITO/PVK/TiO2/Al)。实验发现,器件S1的暗电流远小于器件S2的暗电流,S1的正向峰值光电流约是其反向峰值光电流的4倍,而S2的正向和反向峰值光电流都基本与S1的反向峰值光电流相近。这是由于PVK/TiO2界面处有效的电荷转移、恰当的电荷传输层、器件各层间能级匹配及其与电极功函数的匹配影响了光电流的强度大小。由此判断,器件S1的性能要优于器件S2。随电压的增大,S1结构的光电导响应谱在短波区域的拖尾增大,而S2结构几乎没有拖尾,这可能是两种结构的吸收和陷阱能级的差别造成的。  相似文献   

20.
以硝酸铕、2-(4-氟代苯甲酰基)苯甲酸(HL)、1,10-菲咯啉(Phen)和三苯基氧膦(TPPO)合成了EuL3(H2O)6,EuL3Phen(H2O)4和EuL3(TPPO)(H2O)5三种固态配合物。用元素分析、红外光谱、核磁共振氢谱对配合物进行了组分确定和结构表征。IR表明,2-(4-氟代苯甲酰基)苯甲酸与Eu3+形成配合物后,位于1 692 cm-1处羧基的νCO峰消失,2 500~3 200 cm-1处羧基的νO—H峰也消失,出现了羧酸盐特有的反对称伸缩振动吸收峰(νas(CO-2))和对称伸缩振动吸收峰(νs(CO-2)),且Δν(νas(CO-2)-νs(CO-2))与钠盐的Δν相近,说明羧酸根与Eu3+以对称双齿桥式配位。在1H NMR中,形成配合物后第一配体苯环上的质子峰变为宽峰且移向高场,Phen和TPPO中质子化学位移移向低场。室温下测定了配合物的荧光激发光谱和发射光谱,激发光谱表明配合物EuL3(H2O)6,EuL3Phen(H2O)4和EuL3(TPPO)(H2O)5的最佳激发波长分别为353.0,355.0和357.0 nm;发射光谱均显示Eu3+离子的特征发射光谱,且表明Phen对Eu3+离子的荧光发射有明显增强作用。  相似文献   

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