Some Considerations on Quantum Mechanics—Matter Wave and Probability Wave

It is argued that the distinction between matter wave and probability wave is made clear when the problem is considered from the field-theory viewpoint. Interference can take place for each of these waves, and the similarity as well as dissimilarity between the two cases is discussed.     

量子信息光学

介绍了一门新的学科分支－量子信息光学。它是量子光学与信息科学相结合的产物。光场的量子效应在实现大容量的信息传输，超高精度的信息检测以及不可破译、不可窃听的量子密码术方面有着极其重要的应用前景，在光子学的发展中将发挥独特的作用。该文阐述了量子信息光学中若干物理问题和研究方向，包括超低噪声光源、量子信息复制、量子态工程、量子非破坏性测量和量子密码术。     

Stochastic Dynamics of Reduced Wave Functions and Continuous Measurement in Quantum Optics

The stochastic dynamics of open quantum systems interacting with a zero temperature environment is investigated by employing a formulation of quantum statistical ensembles in terms of probability distributions on projective Hilbert space. It is demonstrated that the open system dynamics can consistently be described by a stochastic process on the reduced state space. The physical meaning of reduced probability distributions on projective Hilbert space is derived from a complete, orthogonal measurement of the environment. The elimination of the variables of the environment is shown to lead to a piecewise deterministic process in Hilbert space defined by a differential Chapman-Kolmogorov equation. A Hilbert space path integral representation of the stochastic process is constructed. The general theory is illustrated by means of three examples from quantum optics. For these examples the microscopic derivation of the stochastic process is given and the general solution of the differential Chapman-Kolmogorov equation is constructed by means of the path integral representation.     

粒子数态波函数推导的新方法

Fock表象是量子光学理论中的基本表象,我们给出粒子数态｜n＞在坐标表象＜x ｜中的波函数的新方法,我们用有序算符内积分技术(IWOP)推导它,这一形式具有简洁优美的特点,并且可推广到其它情形.例如可以探讨在引入双模纠缠态表象后,双模粒子数态的波函数.     

Allowable Generalized Quantum Gates Using Nonlinear Quantum Optics

In this paper, we give an efficient physical realization of a double-slit duality quantum gate. Weak cross- Kerr nonlinearity is exploited here. The probability of success can reach 1/2. Asymmetrical slit duality control gate also can be constructed conveniently. The special quantum control gate could be realized easily in optical system by our current experimental technology.     

Macroscopic Approach to Quantum Optics

This paper investigates how an approach alternative to the canonical quantization schemes may be used to describe Quantum Optics phenomena. By utilizing the approach pioneered by Keldysh, we derive equations for the time dependent correlation functions of the quantized optical fields. These contain the coupling to matter in linear and nonlinar response functions which replace the material parameters of phenomenological macroscopic theories. We present these results as alternatives to existing theoretical methods in Quantum Optics. The paper presents the general formulation of the theory, derives the equations in some specific cases relating to non‐linear optics, and solves some illustrative special cases. We regain known results but also some additional terms deriving from the quantum fluctuations of the material media.     

Scientific Review: Neutron Compton Scattering Unveils Short-Lived Quantum Entanglement of Hydrogen in Condensed Matter

Multiparticle quantum entanglement (QE) and its dynamical properties are in the focus of several experimental and theoretical fields of modern physics and engineering (e.g., quantum optics, quantum computation, quantum cryptography, and teleportation). This is due to the potential applicability of QE for quantum computers and quantum information technology. If the quantum entangled particles are sufficiently isolated from their environment, coherence can persist for long times and quantum phenomena are revealed. However, under realistic conditions, the entangled objects are continuously interacting with their environment. Thus, coherence is lost and classicality emerges. This process is called decoherence [1] and represents the main problem for the realization of a quantum computer.     

量子阱非线性光学研究进展

综述了量子阱非线性光学领域近年来实验工作的进展，重点介绍了共振增强的二阶和三阶非线性效应、光折变效应、量子阱光调制器和ＩＶ族材料的非线性过程，指出该领域发展迅速，应用前景十分广阔。     

Quantum Optics of Ultracold Molecular Fields

We apply concepts of quantum optical coherence to characterize the coherent generation of a molecular field from a quantum-degenerate atomic sample, and discuss the impact of the quantum statistics of the atoms on that field. For atoms initially in a BEC the resulting molecular field is to a good approximation coherent. This is in sharp contrast to the case of atoms in a normal Fermi gas, where we can made use of an analogy with the Tavis-Cummings model to show that the statistics of the resulting molecular field is similar to that of a single-mode chaotic light field. The BCS case interpolates between the two extremes, with an ＇incoherent＇ contribution from unpaired atoms superposed to a ＇coherent＇ contribution from atomic Cooper pairs. We also comment on the temporal fluctuations characteristic of the formation of molecular dimers from ultracold fermionic atoms.     

Dense Baryonic Matter and Neutron Detectors

Promising approaches and methods for studying nuclear matter at high baryonic densities and low temperatures are discussed.     

Neutron Star Matter and Baryonic Interactions

Physics of Atomic Nuclei - The properties of neutron-star matter up to the appearance of hyperons are calculated with the aid of Skyrme potentials. The conditions for the appearance of Λ...     

Neutron Matter Properties Using Skyrme Interaction

The purpose of the present work is to extend earlier nuclear matter calculations to study the properties of neutron matter. The binding energy per particle, symmetry energy, single particle potential, effective mass, and magnetic susceptibility are calculated using a modified Skyrme interaction. These are calculated as a function of the Fermi momentum k_f in the range 0 < k_f < 2 fm^?1. Two sets of the interaction parameters are obtained by fitting the interaction parameters using the available information on neutron matter. Relativistic corrections to the order 1/c² are also calculated. The relativistic corrections are very small and they increase as k_f is increased.     

Neutron Star Matter Including Delta Isobars

In this paper a new phase structure of neutron star matter including nucleons and delta isobars is presented.Particle fractions populated and pion condensations in neutron star matter are investigated in this model. The existence of the pion condensations can postpone the appearance of delta isobars. We found that both the pion condensation and reduce of the ratio of delta isobar to nucleons couplings can soften the corresponding equation of state. The maximum masses and their corresponding radii of neutron stars are calculated, and the obtained values are in observational region.     

Computer-Aided Lecture Experiment on Wave Optics

A complex of lecture demonstrations on wave optics with a personal computer used for control, processing, and representation of the experimental data is described in the present paper. A modern photodetector system built around a photodiode strip is used for recording of the light intensity distribution. The results of application of this complex to the study of dual-beam and multibeam interference of light and of the Fresnel and Fraunhofer types of diffraction by different objects are presented. The developed complex of lecture demonstrations allows the students to refine their understanding of the basic physical phenomena in optics. It also allows the teacher not only to visualize the lecture experiment but also to make it quantitative.     

Quantum Private Comparison Protocol with Linear Optics

In this paper, we propose an innovative quantum private comparison(QPC) protocol based on partial Bell-state measurement from the view of linear optics, which enabling two parties to compare the equality of their private information with the help of a semi-honest third party. Partial Bell-state measurement has been realized by using only linear optical elements in experimental measurement-device-independent quantum key distribution(MDI-QKD) schemes, which makes us believe that our protocol can be realized in the near future. The security analysis shows that the participants will not leak their private information.     

Group Representation of Relativistic Quantum Crystal Optics

A group representation of radiation propagation in an anisotropic medium is developed. The system of wave equations for electromagnetic potentials, obtained from the Maxwell equations with account for the constitutive equations, has been factorized. It is shown that the linear differential operator of the factorized system is orthogonal in transparent crystals and unitary in gyrotropic ones and is represented through the momentum operator. On the basis of the commutation relations for the components of this operator, the eigenvalue problem has been solved and the expression for the change in the radiant energy in the crystal in the form of spherical waves has been obtained. The dependences of the ray and phase velocities and the polarization vectors of waves on the birefringence anisotropy and gyrotropy as well as on the angular momentum, displacement current, and bound charge determining them have been analyzed. It has been established that in the general case of gyrotropic crystals where the nonreciprocity phenomenon takes place and in magnetoelectrics Maxwell equations are represented in a form similar to the Dirac equations and the electromagnetic radiation is correctly described by means of bispinors and is quantized as fermions.