调幅信号对具有量子噪声实虚部关联的饱和激光模型信噪比的影响

在调幅信号的影响下,用线性化近似方法研究了实虚部关联的量子噪声及泵噪声驱动的饱和激光模型的输出功率谱及信噪比.通过计算机数据计算及作图,具体讨论了系统随信号频率、量子噪声实虚部关联度λq、泵噪声强度等变化产生的随机共振现象.结果表明系统在λq=0处出现共振现象,虽然调制信号对系统产生了显著的影响,但由于量子噪声和泵噪声的零关联,系统随其他参数变化时没有随机共振现象.

Partial Teleportation of Entanglement Through Natural Thermal Entanglement in Two-Qubit Heisenberg XXX Chain

Natural thermal entanglement between two qubits with XXX Heisenberg interaction is studied. For the antiferromagnet, increasing coupling strength or decreasing temperature under critical point increases the entanglement. Based on the thermal entanglement as quantum channel, entanglement and information of an input entangled state are transferred via partial teleportation. We find that the entanglement transferred will be lost du~ing the process, and for the entanglement fidelity the partial teleportation is superior to classical communication as concurrence of entangled channel beyond 1/4. We show that both correlation information in input entangled state and individual information of the teleported particle are linearly dissipated. With more entanglement in quantum channel, more entanglement and correlation information can be transferred.

Linear and Nonlinear Optical Absorptions of a Hydrogenic Donor in a Quantum Dot Under a Magnetic Field

The linear and nonlinear optical properties of a hydrogenic donor in a disc-like parabolic quantum dot in the presence of an external magnetic field are studied. The calculations were performed within the effective mass approximation, using the matrix diagonalization method and the compact density-matrix approach. The linear and nonlinear optical absorption coefficients between the ground （L =0） and the first excited state （L = 1） have been examined based on the computed energies and wave functions. We find that the linear, nonlinear third-order, and total optical absorption coefficients are strongly affected by the confinement strength of QDs, the external magnetic field, and the incident optical intensity.

Creation of Entanglement with Nonlocal Operations

We discuss how to create more entanglement with nonlocal operations acting on two-particle states. For a given nonlocal operation, we find that some input states cannot produce entanglement and some produce the maximal entanglement, and find that any initial entangled states can produce more entanglement than initial product states.

GROSS ALPHA DETERMINATION IN URINE

A short review is given for the determination of gross alpha activity ill urine;detailed information is collected including urine mineralization,separation of alpha emitters and source preparation.

Local Invariants for a Class of Tripartite Quantum Mixed States

We study the equivalence of tripartite mixed states under local unitary transformations. The nonlocal properties for a class of tripartite quantum states in C^K× CM ^M×C^N composite systems are investigated and a complete set of invariants under local unitary transformations for these states is presented. It is shown that two of these states are locally equivalent if and only if all these invariants have the same values.

Invariants for a Class of Nongeneric Three-Qubit States

We investigate the equivalence of quantum states under local unitary transformations. A complete set of invariants under local unitary transformations are presented for a class of non-generic three-qubit mixed states. It is shown that two such states in this class are locally equivalent if and only if all these invariants have equal values for them.

Effects of Spin Quantum Force in Magnetized Quantum Plasma

Starting from the governing equations for a quantum magnetoplasma including the electron spin -1/2 effects and quantum Bohm potential, we derive Korteweg-de Vries （KdV） equation of the system of quantum magneto- hydrodynamics （QMHD）. The amplitude and width of magnetosonic soliton with different parameters in the system are studied. It is found that the normalized Zeeman energy E plays a crucial role, for E ≥ 1 the amplitude τmξ and the width we of solitary wave all decrease as E increases. That is, the introduction of spin quantum force modifies the shape of solitary magnetosonic waves and makes them more narrower and shallower.

Magnetic Effects in Brain Chemistry

Abstract： Chemistry of the human brain has two components--the basic chemistry common to all mammals and chemistry of thinking inherent to man. The authors proposed a mechanism of induction and thermodynamic features of the brain. The authors offered the mechanisms of the work RAM （physical） and permanent （chemical）, the brain＇s memory, including the model of nonlocal quantum correlations.

Matrix Tensor Product Approach to the Equivalence of Multipartite States under Local Unitary Transformations

The equivalence of multipartite quantum mixed states under local unitary transformations is studied. A criterion for the equivalence of non-degenerate mixed multipartite quantum states under local unitary transformations is presented.

Controlled Implementation of Non-local CNOT Operation Using Three-Qubit Entanglement

We investigate the controlled implementation of a non-local CNOT operation using a three-qubit entangled state. Firstly, we show how the non-local CNOT operation can be implemented with unit fidelity and unit probability by using a maximally entangled GHZ state as controlled quantum channel. Then, we put forward two schemes for conclusively implementing the non-local operation with unit fidelity by employing a partially entangled pure GHZ state as quantum channel. The feature of these schemes is that a third side is included, who may participate the process of quantum non-local implementation as a supervisor. Furthermore, when the quantum channel is partially entangled,the third one can rectify the state distorted by imperfect quantum channel. In addition to the GHZ class state, the W class state can also be used to implement the same non-local operation probabilistically. The probability of successful implementation using the W class state is always less than that using the GHZ class state.

Experimental study on dispersive soil in western Jilin

In order to research engineering geological properties of the soil in Zhenlai of western Jilin, especially the dispersivity of soil, the authors carried out the basic physicocbemical test and dispersivity identification test. The results show that the dispersivity of the soil increases with the increase of depth within 0-30 cm （surface soil） ; it decreases as the depth increases within in 30-100 cm. Furthermore, the statistical analysis of the dispersivity indexes and physicochemical propertity indexes show that the DP is positively linear correlated with total soluble salt content, sodium ion content, ESP, pH and organic matter content. Meanwhile, it is negatively linear correlated with clay content, and the linear relationship is better. Through the study of the dispersion mechanism of soil samples, it can be concluded that sodium montmorillonite, higher percentage of exchangeable sodium and high pH are the main reasons for the dispersion of soils in western Jilin.

Host Engineering for Red Electrophosphorescent Devices

In this paper, we demonstrate that controlled dopantoncentration is an essential issue for charge carriers transporting in red Phosphorescent Organic Light-Emitting Device （PHOLED）. Carriers transport via dopant molecules in the emitting layer with a single host, however, via both dopant and host molecules when their energy levels are well aligned. Conditions for reduced driving-voltage and enhanced efficiency of red PHOLED are obtained by employing a mixed host structure. A pure red PHOLED with color coordinates of （0.67, 0.33） has been realized by using only 4 wt% dopant, The device achieves 100 cd/cm2 at 2.9 V, with correspond- ing power efficiency of 9.3im/W and external quantum efficiency of 14.3%.

Electric properties of Ge quantum dot embedded in Si matrix

The electric characteristics of Ge quantum dot grown by molecular beam epitaxy in Si matrix were investigated by admittance spectroscopy and deep level transient spectroscopy. The admittance spectroscopy measurements show that the activation energy of 0.341eV can be considered as the emitting energy of hole from the ground state of the quantum dot. And the capacitance variation with temperature of the sample shows a platform at various frequencies with reverse bias (0.5 V,) which indicates that the boundary of space charge region is located at the quantum dot layer where the large confined hole concentration blocks the further extension of space charge region. When the temperature increases from 120K to 200K, the holes in the dot emit out completely. The position of the platform shifting with the increase of the applied frequency shows the frequency effects of the charges in the quantum dot. The deep level transient spectroscopy results show that the charge concentration in the Ge quantum dot is a function of the pulse duration and the reverse bias voltage, the activation energy and capture cross-section of hole decrease with the increase of pulse duration due to the Coulomb charging effect. The valence-band offsets of hole in Ge dot obtained by admittance spectroscopy and deep level transient spectroscopy are 0.341 and 0.338eV, respectively.

Non-Abelian Geometric Manipulation of a Crystal of Molecular Nanomagnet Mn_(12)

Based on the strong magnetic anisotropy along the symmetry of the crystal, we construct a U（2） non-Abelian gauge potential for the molecular nanomagnet Mn12 by varying the external magnetic field adiabatically. Moreover, the non-Abelian geometric phase and the unitary matrix operation, which are tile key steps to realize the universal holonomic quantum computing in the degenerate subspace, are also obtained by means of choosing an evolution path properly.

Non-unitary Scattering Theory against Generalized Unitary Scattering Theory

Comparison of non-unitary and generalized unitary scattering theories is done by means of nuclear monodromy （equivalence of Schrodinger and Maxwell time-independent equations）, tunneling and radioactivity. Radioactivity is important part of physics and our life. Its importance stretches from medicine as far as to war strategies. We present theoretical approach to achieve better understanding of the radioactive decay when modified quantum theory is applied. It can be done by updating existing codes to understand better construction of the world and terms and conditions of our existence. The theory modifications are strictly connected with the unimodular M matrix and Wronskian matrices （i.e. their determinants named Wronskians） which create underpinning of so called monodromy being two track wave-function evolution.

Entanglement of a Five-Qubit Heisenberg XX Chain in a Magnetic Field

We calculate the eigenvalues and eigenvectors of a five-qubit isotropic Heisenberg model in an external magnetic field, and give analytical results for the concurrence of two nearest-neighbor qubits. A magnetic field can eliminate degeneration and change the ground state of the system. Therefore increasing the value of the magnetic field can induce entanglement in a certain range both for the antiferromagnetic and ferromagnetic case.

Violation of Locality Beyond Bell＇s Theorem for Multiparticle Perfect Correlations

We present the analogous inequalities of Bell's inequality for N-qubit system predicted respectively by realistic theory, quantum mechanics, local theory, local realistic theory, and local quantum theory on the same Belltype joint experiment. It is shown that quantum mechanics can be interpreted by hidden-variable theories while being incompatible to any local theory. A necessary condition for the separability of N-qubit system is derived.

Two Electrons with Spin-Orbit Interactions in InAs Coupled Quantum Dots

We theoretically study the spin properties of two interacting electrons confined in the IhAs parallel coupled quantum dots （CQDs） with spin-orbit interactions （SOI） by exact diagonalization method. Through the SOI induced spin mixing of the singlet and the triplet states, we show the different spin properties for the weak and strong SOI. We investigate the coherent singlet-triplet spin oscillations of the two electrons under the SOI, and demonstrate the detailed behaviors of the spin oscillations depending on the SOI strengths, the inter-dot separations and the external magnetic fields. To better understand the underlying physics of the spin dynamics, we introduce a four-level model Hamiltonian for both weak and strong SOI, and find that the SOI induced in plane effective magnetic fields can be quantitatively extracted from the two-electron excitation energy spectra.