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We construct the 1D $\mathbb{Z}_3$ parafermionic model based on the solution of Yang-Baxter equation and express the model by three types of fermions. It is shown that the $\mathbb{Z}_3$ parafermionic chain possesses both triple degenerate ground states and non-trivial topological winding number. Hence, the $\mathbb{Z}_3$ parafermionic model is a direct generalization of 1D $\mathbb{Z}_2$ Kitaev model. Both the $\mathbb{Z}_2$ and $\mathbb{Z}_3$ model can be obtained from Yang-Baxter equation. On the other hand, to show the algebra of parafermionic tripling intuitively, we define a new 3-body Hamiltonian $\hat{H}_{123}$ based on Yang-Baxter equation. Different from the Majorana doubling, the $\hat{H}_{123}$ holds triple degeneracy at each of energy levels. The triple degeneracy is protected by two symmetry operators of the system, $\omega$-parity $P$($\omega=e^{{\textrm{i}\frac{2\pi}{3}}}$) and emergent parafermionic operator $\Gamma$, which are the generalizations of parity $P_{M}$ and emergent Majorana operator in Lee-Wilczek model, respectively. Both the $\mathbb{Z}_3$ parafermionic model and $\hat{H}_{123}$ can be viewed as SU(3) models in color space. In comparison with the Majorana models for SU(2), it turns out that the SU(3) models are truly the generalization of Majorana models resultant from Yang-Baxter equation., Comment: Main text: 12 pages; Supplementary: 4 pages

The role of $\ell_{1}$-norm in Quantum Mechanics (QM) has been studied through Wigner's D-functions where $\ell_{1}$-norm means $\sum_{i}\left|C_{i}\right|$ for $\left|\Psi\right\rangle =\sum_{i}C_{i}\left|\psi_{i}\right\rangle $ if $\left|\psi_{i}\right\rangle $ are uni-orthogonal and normalized basis. It was shown that the present two types of transformation matrix acting on the natural basis in physics consist in an unified braiding matrix, which can be viewed as a particular solution of the Yang-Baxter equation (YBE). The maximum of the $\ell_{1}$-norm is connected with the maximally entangled states and topological quantum field theory (TQFT) with two-component anyons while the minimum leads to the permutation for fermions or bosons., Comment: 17 pages, 5 figures

In this paper we describe connections among extraspecial 2-groups, unitary representations of the braid group and multi-qubit braiding quantum gates. We first construct new representations of extraspecial 2-groups. Extending the latter by the symmetric group, we construct new unitary braid representations, which are solutions to generalized Yang-Baxter equations and use them to realize new braiding quantum gates. These gates generate the GHZ (Greenberger-Horne-Zeilinger) states, for an arbitrary (particularly an \emph{odd}) number of qubits, from the product basis. We also discuss the Yang-Baxterization of the new braid group representations, which describes unitary evolution of the GHZ states. Our study suggests that through their connection with braiding gates, extraspecial 2-groups and the GHZ states may play an important role in quantum error correction and topological quantum computing., v1: Latex, 28 pages; v2: comment and references added; v3: Title and authors changed. Significantly more concise than previous versions, now 21 pages

We propose a scheme to generate quantum spin current via optical dipole transition process. By coupling a three-level system based on the spin states of charged particles (electrons or holes in semiconductor) to the angular momentum states of the radiation, we show that a pure quantum spin current can be generated. No spin-orbit interaction is needed in this scheme. We also calculate the effect of nonmagnetic impurities on the created spin currents and show that the vertex correction of the spin hall conductivity in the ladder approximation is exactly zero., 5 pages, 3 figures

Entanglement of remote atom lasers is obtained via quantum state transfer technique from lights to matter waves in a five-level $M$-type system. The considered atom-atom collisions can yield an effective Kerr susceptibility for this system and lead to the self- and cross- phase modulation between the two output atom lasers. This effect results in generation of entangled states of output fields. Particularly, under different conditions of space-dependent control fields, the entanglement of atom lasers and of atom-light fields can be obtained, respectively. Furthermore, based on the Bell-state measurement, an useful scheme is proposed to spatially separate the generated entangled atom lasers., 8 pages, 3 figure

It is fundamental to view unitary braiding operators describing topological entanglements as universal quantum gates for quantum computation. This paper derives a unitary solution of the Quantum Yang--Baxter equation via Yang--Baxterization and constructs the Hamiltonian responsible for the time-evolution of the unitary braiding operator., v1, 11 pages; v2, 11 pages; v3, 12 pages, additional comments; v4, 10 pages; v5, published version

The dynamics of the domain wall (DW) in a biaxial ferromagnet interacting with a spin-polarized current are described by sine-gordon (SG) equation coupled with Gilbert damping term in this paper. Within our frame-work of this model, we obtain a threshold of the current in the motion of a single DW with the perturbation theory on kink soliton solution to the corresponding ferromagnetic system, and the threshold is shown to be dependent on the Gilbert damping term. Also, the motion properties of the DW are discussed for the zero- and nonzero-damping cases, which shows that our theory to describe the dynamics of the DW are self-consistent., 7pages, 3figures

A model for coexistence of p-wave spin-triplet superconductivity (SC) and itinerant ferromagnetism (FM) is presented. The Hamiltonian can be diagonalized by using the so(5) algebraic coherent state. We obtain the coupling equations of the magnetic exchange energy and superconducting gaps through the double-time Green function. It is found that the ferromagnetisation gives rise to the phase transitions of p-wave superconducting states or superfluid of $^{3}He$., 9 pages, no figures

The wave function describing two-component Bose-Einstein condensate with weakly excitations has been found, by using the SO(3,2) algebraic mean-field approximation. We show that the two-component modified BEC (see eq.(\ref{ga})) possesses uniquely super-Poissonian distribution in a fixed magnetic field along z-direction. The distribution will be uncertain, if B=0., 15 pages, no figures

The quantum nonlinear Schr$\ddot{o}$dinger(NLS) model with four-component fermions exhibits a $Y(so(5))$ symmetry when considered on an infintite interval. The constructed generators of Yangian are proved to satisfy the Drinfel'd formula and furthermore, the $RTT$ relation with the general form of rational R-matrix given by Yang-Baxterization associated with $so(5)$ algebraic structure., 10 pages, no figures

A unified treatment is developed for the XXX-Heisenberg model and a long-ranged interaction model (the $H_2$ in Haldane-Shastry model) from the point of view of shift operators (or raising and lowering operators), based on which the energy spectra of the spin-chain models are determined. Some physical discussions are also made., 26 pages, Latex file, Submitted to J. Phys. A

The shift operators for XXX-Heisenberg chain are found. They are formed by local Yangian operators and the amplitutes of the eigenfunctions obeying Bethe ansatz for the Hamiltonian. The physical implication of the shift operators are also explained., 12 pages, Latex file

The relation between CP-violation phase angle and the other three mixing angles in Cabibbo-Kobayashi-Maskawa matrix is postulated. This relation has a very definite geometry meaning. The numerical result coincides surprisingly with that extracting from the experiments. It can be further put to the more precise tests in the future., 7 pages, Latex file, the revised version for resubmitting