The quantum traditional adiabatic theorem was present and traditional approximation conditions were given. Based on existence of insufficence about quntum traditional adiabatic approximation condition, the new adiabatic theory and new adiabatic approximation condition were proposed and discussed by means of perturbative approach and U(1)-invariant expasion. The properties of quantum geometric potential contained in the new adiabatic condition were analyzed and discussed.
Based on the important position and application of abnormal Boson quantum system in the theory of relativistic covariant vector field of zero quality, the specific form of eigenket of the abnormal Boson creation operator can be derived by virtue of the contour integral representation of Dirac-function and its properties as well as feature of the number representation of abnormal Boson system. Furthermore, two sets of new orthogonality and completeness relations, which are irrelevant to normality operator, were obtained. Finally, as an applications, it was used to rewrite the expressions of Hermite polynomial and Laguerre polynomial under meaning of the contour integral, which presumably provide help for some questions of quantum optics about these polynomials.
By applying the extended simplest equation method, the new exact traveling wave solutions of the Whitham-Broer-Kaup-Like equations were successfully constructed. The exact traveling wave solutions with double arbitrary parameters are expressed by the hyperbolic functions, the trigonometric functions and the rational functions respectively. When the parameters are taken as special values, some solitary wave solutions are derived from the hyperbolic function solutions. The obtained results illustrate that the extended simplest equation method is direct, reliable and effective and can be used to obtain more exact traveling wave solutions of other nonlinear evolution equations in mathematical physics.
The single longitudinal mode (SLM) operation characteristics of a compound ring cavity fiber laser based on cascaded fiber rings formed by single and dual optical coupler (OC) was investigated. By analyzing the resonating pass-band properties of cascaded fiber rings with respectively single and dual OC, a method to optimize the resonating pass-band properties of the dual-OC fiber ring for achieving stable SLM operation was given. With a compound ring cavity erbium-doped fiber laser based on such cascaded fiber rings, the optimization method for achieving stable SLM operation was verified experimentally. For the length of the main ring, the single-OC ring and dual-OC ring are respectively 6.8, 0.45 and 0.56 m, the operation for SLM with the fiber laser is observed to be most steadily when the coupling ratio of the two OCs in the dual-OC fiber ring is chosen to be 0.7. The experimental results are in agreement with the theoretical analysis.
The light absorption properties of Nd:YVO4 laser crystals at 808 nm were studied. The relationship between doped concentration and absorption coefficients was measured and calculated. Based on the transmission test, the absorption coefficients of Nd:YVO4 crystals were calculated. It is a determined value which is irrelevant to the pump power under the conditions of certain concentration and length of the crystal. The polarized π and σ absorption were calculated and the relationship between them was compared.
The nonclassical properties such as antibunching effect, violation of Cauchy-Schwarz inequality and two-mode squeezing of the pair coherent states based on a non-degenerate two-photon Jaynes-Cummings model were investigated. It is shown that these nonclassical properties can be enhanced in the case that the coefficients are chosen appropriately or the atom is selectively detected. In addition, all kinds of the nonclassical properties by using Ξ-type three-level atom are more effective than that using Λ-type three-level atom.
Based on the parameters of posterior distribution of bit error rate (BER) regarding parity check-Hamming correction protocol, the BER and its confidence interval of the remaining quantum keys were directly estimated. In experiment, instead of the raw quantum keys, two pseudo-random binary sequences were used which have the length of 1.4×10-7 and the BER follow binomial distribution. The error correction process utilizes the parity code and Hamming code for error detection correction respectively. The experimental results showed that when the initial bit error rate at 3% and 0.1%, by one time error detection and error correction, the BER falls to 2.47×10-3 and 1.43×10-7 respectively, when the confidence at 95%, the corresponding upper limit of BER at 2.77×10-3 and 10.57×10-7 respectively. These experimental results effectively assessed parity-Hamming error correction performance on the finite quantum keys, and provided reliable data for the post-processing in the quantum key distribution.
With the booming development of quantum cryptography, the free-space quantum key distribution is an important research branch. It will play a critical role in the future global quantum communication. The electronic design of quantum key distribution (QKD) control system based was presented on a Xilinx’s VirtexII-Pro series chip. Extracting final quantum key and controlling peripheral circuit were implemented with the combination of the embedded hard core PowerPC405 in FPGA and the logic module designed by very-high-speed integrated circuits hardware description language (VHDL). The design was applied in the 1 km QKD distribution experiment during daytime, and its final key rate was greater than 1.5 kbps.
A CNOT gate is an important quantum component for quantum computation, which is widely used in fault-tolerant extended-rectangle construction. However, the ancilla state preparation circuit is normally complicated in the construction of fault-tolerant extended-rectangle for quantum CNOT gates, which brings inconvenience in the design and implementation. A novel construction of fault-tolerant quantum CNOT gates using (49,1,9) quantum code is presented using overlap method to simplify the encoded ancilla preparation state circuit. The result shows that the construction is optimized and the number of CNOT gates needed is 224 less than that with the traditional Latin rectangle method.
A scheme of quantum teleportation was proposed, with a set of two-qubit maximally entangled states and three-qubit partially entangled states as a shared quantum channel, where the three-qubit partially entangled states as the channel can be physically realized from the generalized Greenberger-Horne-Zeilinger (GHZ) states by performing a H(Hadamard) gate and a CNOT gate on it. Compared to the channels of the general three-particle states, the states allow the transfer of a maximum number of bits from the sender to the receiver. The sender Alice measures her qubits in the Bell basis, then tells the measurement results to controller Charlie from a classical channel, now Charlie measures his qubits in the partially entangled Bell basis, and tells Bob of the results, at last in order to recover the teleported states successfully, Bob needs to perform a corresponding unitary transformation. In addition, this program uses a non-maximally entangled states as a shared channel, under the control of Charlie, the probability of the successful quantum teleportation may reach 100%.
To improve computation speed and efficiency of genetic algorithm-partial square least (GA-PLS), a novel feature selection algorithm which combines quantum computation and GA-PLS (QGA-PLS) was proposed. In QGA-PLS algorithm, qubits and superposition of states were used for chromosome code. Quantum rotation gate was used for genetic operation to update parameters and enhance population diversity. Meanwhile, with PLS model which was reconstructed by quantum computing, the value of individual adaptability was calculated. Rapid convergence and good global optimization capability characterize the performance of QGA-PLS. The proposed method was applied to two simulation experiments, extreme value of a function and feature selection for Iris dataset. The experimental results indicated that, compared with QGA and GA-PLS, QGA-PLS has better performance in feature selection, execution time and classification accuracy, which proves the efficiency of proposed method.
The dark state of a three-core waveguide was adapted to study the influence of the nonlinearity on the coherent population trapping (CPT) by Silberberg, etc. However, the numerical result of such a waveguide shows that both the CPT and nonlinear self-trapping can result in the dark states. When both effects occur, the dark states will be destroyed. Thus the destruction of dark states are due to the both effects, which means one cannot simply attribute the disappearance of darks states to the CPT solely. In the ideal CPT case, the critical power of nonlinearity approaches to infinity, which means that the nonlinearity of the system does not influence the ideal CPT quantum effects.
Based on the basic theoretical model of spatial optical solitons in no-local nonlinear medium, using the subsection Fourier algorithm, the transmission characteristics and stability of the spatial optical solitons in two-dimensional no-local nonlinear media were studied. The results reveal that in the medium, Laguerre-Gauss soliton (LGs) can exist. The transmission properties of soliton can be controlled by the modulation depth coefficient, as well as the initial conditions of beam condition in the no-local media. Furthermore. It’s found that the bigger of the transmission distance, the greater the effect is. The results can improve and enrich the spatial soliton theory system.
Contents of Ca and Mg in the slag were analyzed quantitatively with laser-induced breakdown spectroscopy (LIBS). Due to the complexity of the slag composition a regression relationship established often fails to get the desired result, this results in that the problem of multiple variable regression analysis must be considered. In order to analyze the contents of Ca and Mg in the slag, the Mg, Ca, Fe, Si, Al atomic line intensity and Mg, Ca ion line intensity were used as the input vectors. However, when the absolute line intensity including strong spectral lines and weaker spectral lines are put together as the input vector, the influence of the former will cover up the latter. Spectral intensity needs treated first to place all the values of the line intensities in a similar range. The slag composition analysis were then performed and compared using three calibration methods like nonlinear multi-function, BP neural network and radial basis function (RBF) network. In addition, the advantage of the RBF neural network calibration relative to traditional non-linear calibration method was particularly emphasized.
In order to find out rule of sintering temperature of hydroxyapatite(HA) target, the powder of 99% pure hydroxyapatite was pressed to discal targets and the targets were sintered at 600C, 700C and 800C in argon ambience respectively. The targets stinered at different temperatures and the targets not sintered were detected with X-ray diffractometer(XRD) and the X-ray photoelectron spectroscopy(XPS). The experimental result demonstrates that sintering temperature does not influence on the composition and crystallinity of all kinds of targets observably, but the average particle diameter and the ratio of Ca to P of hydroxyapatite targets should increase if sintering temperature rise. The hydroxyapatite target sintered at 800C has the best biocompatibility, bioactivity and stability.
Based on Boltzmann transport equation and Landauer equation, characteristics of the thermoelectric parameters such as the figure of merit, electrical conductance and power factor for two kinds of modulus were studied, including a constant and a Gauss-typed distribution functions with a finite energy spectrum width. Compared with Delta-typed modulus, it is found that the figure of merit decreases but the electrical conductance and the power factor increases after the spectrum width is introduced. The thermoelectric performance of the two kinds of modulus is more practically meaningful than that of the Delta-typed modulus.
In order to overcome the shortcoming involved with the current theory, the new theory model of lattice vibration in Ax B1-x Cy D1-y quarternary mixed crystals was described. Using the Clausius-Mossotti formula for simplifying the motion equations, and Born-Huang equations for eliminating microscopic variables, the relationship between optical phonon and elemental concentrations (x,y) of mixed crystals was obtained. The advantage of the proposed theory model is that the optical phonon character of Ax B1-x Cy D1-y quarternary mixed crystals can be solved only by several parameters of the binary mixed crystals such as AC, AD, BC and BD. The parameters include TO mode frequency, LO mode frequency, static dielectric constant and optical dielectric constant. Taking the boundary values, the results are corresponding to ternary mixed crystals and binary mixed crystals. The theoretical results and experimental data meet well with each other, which give certain guidance to future experiments.
The relationship between quantum dot and energy level was analyzed using a simple model and the equation about the energy level and quantum dot size was developed. The electron wave function within quantum dot does not fully meet the standing wave condition for the existence of surface wave attenuation, so a correction factor expression was introduced combined with the equation about energy level of quantum dot. And the calculation method of the correction factor was introduced. The theory calculation shows that the gap between energy level of quantum dot is not only related to the quantum dot size but its boundary conditions. The surface potential barrier has an important impact on the energy level of the quantum dot and the energy gap especially for non-smooth surface.
Based on the loss parameters of silicon waveguide, waveguide crossing and microresonator based optical switching elements, a general analytical model to study the transmission loss in Torus-based optical network on chip (ONoC) was proposed. The model was used to analyze insertion loss at device level, router level and network level. Meanwhile, the automatic analysis system was established. The maximal insertion loss in different network scales was obtained from the analysis system. The maximal insertion loss of the Torus-based ONoC using the Crossbar, Cygnus and Crux was also analyzed. From the numerical investigation, it can be obtained that the insertion loss enlarges with the increasing network scale and the minimum insertion loss is presented at condition of M=N. Meanwhile, compared with the Crossbar and Cygnus, the insertion loss of the ONoC using Crux is minimum. The insertion loss of the ONoC using Crux is less than the insertion loss of the ONoC using Cygnus about 5 dB.
The characteristics of EM in dielectric-metal-dielectric (MDM) surface plasmon polaritons (SPPs) waveguides were presented. The numerical results show that the waveguide can only excitate the first order SPP mode (fundamental mode) for the wavelength of 633 nm, if the dielectric film thickness is less than 85 nm. With the dielectric film thickness increasing, progressively high order SPP modes are excited. The real part of the effective refractive index decreases with increasing the order of the SPP modes, but that of the imaginary part shows an opposite trend. However, when the dielectric layer of the MDM waveguide thickness is more than 0.555 μm, since the third-order mode of the electromagnetic field SPP concentrated in relatively distant from the metal layer, the effective refractive index has a minimum value of the imaginary part. So the third-order SPP mode has a maximum propagation distance. When the wavelength of the incident light is 633 nm, the dielectric layer thickness is 0.9 μm Ag/SiO2 /Ag, the transmission distance of the third-order SPP mode is about 150 μm in the waveguide.