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Quantum correlations play vital roles in the quantum features in quantum information processing tasks. Among the measures of quantum correlations, quantum discord (QD) and entanglement of formation (EOF) are two significant ones. Recent research has shown that there exists a relation between QD and EOF, which makes QD more significant in quantum information theory. However, until now, there exists no general method of characterizing quantum discord in high-dimensional quantum systems. In this paper, we have proposed a general method for calculating quantum discord in arbitrary-dimensional bipartite quantum systems in terms of Hurwitz's theory. Applications including the Werner state, the spin-1 XXZ model thermal equilibrium state, the Horodecki state, and the separable-bound-free entanglement state are investigated. We present the method of obtaining the EOF of arbitrary-dimensional bipartite quantum states via purification, and the relationship between QD and EOF.

The interacting boson model-3 (IBM-3) has been used to study the energy levels and electromagnetic transitions for the nucleus 34S. The main components of the wave function, isoscalar and isovector parts in the M1 and E2 transitions for low-lying states have been investigated. According to this study, the theoretical calculations are in agreement with experimental data, and the nucleus 34S is in transition from U(5) to SU(3).

In this paper two kinds of two-boson realizations of generally deformed algebras with three generators are obtained by generalizing the Jordan-Schwinger realizations of SU(2) and SU(1,1). For each kind, a. unitary realization and a non-unitary realization, together with the properties of their acting spaces, are discussed. Similarity transformations that relate tile non-unitary realizations to tile unitary ones are given by solving unitarization equations.

A measuring-basis encrypted quantum key distribution scheme is proposed by using twelve nonorthogonal states in a four-state system and the measuring-basis encryption technique. In this scheme, two bits of classical information can be encoded on one four-state particle and the transmitted particles can be fully used.

The angular-momentum projection part of RECAPS is presented. Application of RECAPS to some deformed nuclei is also presented.

Two kinds of M-particle d-dimensional Schmidt-form entangled state teleportation protocols are presented. In the first protocol, the teleportation is achieved by d-dimensional Bell-basis measurements, while in the second protocol it is realized by d-dimensional GHZ-basis measurement.

The quantum nature of bulk ensemble NAIR quantum computing - the center of recent heated debate, is addressed. Concepts of the mixed state and entanglement arc examined, and the data in a two-qubit liquid NAIR quantum computation are analyzed. The main points in this paper are: i) Density matrix describes the "state" of an average particle in an ensemble. It does not describe the state of an individual particle in an ensemble; ii) Entanglement is a property of the wave function of a microscopic particle (such as a molecule in a liquid NAIR sample), and separability of the density matrix cannot be used to measure the entanglement of mixed ensemble; iii) The state evolution in bulk-ensemble NAIR quantum computation is quantum-mechanical; iv) The coefficient before the effective pure state density matrix, c, is a measure of the simultaneity of the molecules in an ensemble. It reflects the intensity of the NAIR signal and has no significance in quantifying the entanglement in the bulk ensemble NAIR system. The decomposition of the density matrix into product states is only an indication that the ensemble can be prepared by an ensemble with the particles unentangled. We conclude that effective-pure-state NAIR quantum computation is genuine, not just classical simulations.

The positive-parity collective states in the even-even Te isotopes are studied in the framework of interacting boson model. A schematic Hamiltonian able to describe the transition from to dynamical symmetry is used. It is found that the spectra can be well described by the transition from vibration to rotation. The behavior of the state can be partially described by the model, suggesting that the state is mainly composed of the normal sd configuration, but is influenced by the cross-shell excitation across the shell.

A misunderstanding that an arbitrary phase rotation of the marked state together with the inversion about average operation in Grover's search algorithm can be used to construct a (less efficient) quantum search algorithm is cleared. The $\pi$ rotation of the phase of the marked state is not only the choice for efficiency, but also vital in Grover's quantum search algorithm. The results also show that Grover's quantum search algorithm is robust., Comment: 5 pages, 5 figures