New gauge boson and spin correction of top quark pair production at ILC

Based on the SU(3) simple group model , we study the spin correction of the top quark pair production at the high energy linear e+e- collider (ILC) with a center-of-mass energy =800GeV. Our numerical results show that the gauge boson ZH exchange generates very small corrections to the spin correction observable in all the parameter space, which can not be detected in the future ILC experiments.

Energy spectrum and superfluidity of spin-2 ultracold bosons in optical lattices

This paper studies the superfluidity of ultracold spin-2 Bose atoms with weak interactions in optical lattices by calculating the excitation energy spectrum using the Bogoliubov approach. The energy spectra exhibit the characteristics of the superfluid-phase explicitly and it finds the nonvanishing critical speeds of superfiuid. The obtained results display that the critical speeds of superfiuid are different for five spin components and can be controlled by adjusting the lattice parameters in experiments. Finally it discusses the feasibilities of implementing and measuring superfluid.

Coherent incoherent transition in the spin boson model with a super-ohmic bath

The temperature effect on tunnelling splitting in the spin boson model with a super-ohmic bath is studied by the small polaron theory. The coherent-incoherent transition temperature is calculated and its dependence on dissipation strength and bare tunnelling splitting is analysed. In additional to the traditional transition point described in textbooks, a new kind of transition is found in the low dissipation region, showing different temperature dependence in the transition. The relation to the corresponding transition in the polaron-phonon system is also discussed.

A note on localized transition in the spin-boson model by variational calculation

We present mathematical analyses of the evolution of solutions of the self-consistent equation derived from variational calculations based on the displaced-oscillator-state and the displaced-squeezed-state in spin-boson model at a zero temperature and a finite temperature. It is shown that, for a given spectral function defined as J（w） = π∑k Ck^2 = π/2αw^8w^1-s, there exists a universal sc for both kinds of variational schemes, the localized transition happens only for 2 s ≤ sc, moreover, the localized transition is discontinuous for s 〈 sc while a continuous transition always occurs when s = sc. At T = 0, we have sc = 1, while for T ≠ 0, sc = 2 which indicates that the localized transition in super-Ohmic case still exists, manifesting that the result is in discrepancy with the existing result.

Quantum parameter estimation in a spin-boson dephasing quantum system by periodical projective measurements

In this paper,we explore how to estimate the phase damping parameter γ and the tunneling amplitude parameter ？from a spin-boson dephasing quantum model by periodical projective measurements.The preparation of initial states is accomplished by performing the period measurements in our scheme.The parameter γ can be always estimated when projective measurement bases are chosen as θ = π/2 and φ = 0.Based on the estimated value of γ and the interval information of ？,we can select another measurement bases（θ = π/4 and φ = π/2） to obtain the estimated value of ？.A coherent control is indispensable to estimate ？ if γ is in the interval of ？;whereas the control is not necessary if γ is out of the known interval of ？.We establish the relation between the optimal period time and the parameter γ or ？ in terms of Fisher information.Although the optimal measurement period cannot be selected beforehand,the aforementioned relation can be utilized to adjust the measurement period to approach the optimal one.

Equilibrium dynamics of the sub-Ohmic spin-boson model under bias

Using the bosonic numerical renormalization group method, we studied the equilibrium dynamical correlation function C（ω） of the spin operator σz for the biased sub-Ohmic spin-boson model. The small-ω behavior C（ω） ∝ ω～s is found to be universal and independent of the bias ε and the coupling strength α（except at the quantum critical point α = αc and ε = 0）. Our NRG data also show C（ω） ∝ χ～2ω～s for a wide range of parameters, including the biased strong coupling regime（ε = 0 and α 〉 αc）, supporting the general validity of the Shiba relation. Close to the quantum critical point αc,the dependence of C（ω） on α and ε is understood in terms of the competition between ε and the crossover energy scale ω0^＊of the unbiased case. C（ω） is stable with respect to ε for ε《ε^＊. For ε 》ε^＊, it is suppressed by ε in the low frequency regime. We establish that ε^＊∝（ω0^＊）^1/θ holds for all sub-Ohmic regime 0≤s 〈 1, with θ = 2/（3s） for 0 〈 s≤1/2 and θ = 2/（1 ＋ s） for 1/2 〈 s 〈 1. The variation of C（ω） with α and ε is summarized into a crossover phase diagram on the α–ε plane.

Dynamical correlation functions of the quadratic coupling spin-Boson model

The spin-boson model with quadratic coupling is studied using the bosonic numerical renormalization group method.We focus on the dynamical auto-correlation functions CO（ω）, with the operator taken as σx, σz, and X, respectively. In the weak-coupling regime α 〈 αc, these functions show power law ω-dependence in the small frequency limit, with the powers 1 ＋ 2s, 1 ＋ 2s, and s, respectively. At the critical point α = αc of the boson-unstable quantum phase transition, the critical exponents yO of these correlation functions are obtained as yσx= yσz= 1-2s and yX=-s, respectively. Here s is the bath index and X is the boson displacement operator. Close to the spin flip point, the high frequency peak of Cσx（ω） is broadened significantly and the line shape changes qualitatively, showing enhanced dephasing at the spin flip point.

Spin Forms and Spin Interactions among Higgs Bosons, between Higgs Boson and Graviton

This paper offers concrete spin matrix forms of 0h spin zero particle, and shows the existent of the spin interactions among 0h spin zero particles. It is obviously hoping to approach, on the most comprehensive level, to understand what really Higgs Boson is and what role-play Higgs Boson is acting in particle physics. As a "particle" of gravitational force, the spin interaction between 0h spin zero particle (Higgs Boson) and 2h spin particle (Graviton) is given, which maybea way that people would find Graviton in future.

Ultrafast magneto-optical dynamics in nickel(111)single crystal studied by the integration of ultrafast reflectivity and polarimetry probes

With the integration of ultrafast reflectivity and polarimetry probes,we observed carrier relaxation and spin dynamics induced by ultrafast laser excitation of Ni(111)single crystals.The carrier relaxation time within the linear excitation range reveals that electron-phonon coupling and dissipation of photon energy into the bulk of the crystal take tens of picoseconds.On the other hand,the observed spin dynamics indicate a longer time of about 120 ps.To further understand how the lattice degree of freedom is coupled with these dynamics may require the integration of an ultrafast diffraction probe.

反旋转波相互作用对非平衡自旋玻色模型热输运性质的影响

随着实验技术的发展,量子系统中已经实现了强和超强自旋-腔、自旋-环境相互作用。很大一类光学腔和耗散环境可以用波色热库描述。在强系统-热库耦合条件下,之前适用于弱耦合条件下的旋波近似失效,需要考虑系统-热库的反旋转波相互作用对系统动力学演化和稳态行为的影响。使用正则变换和全计数统计方法,研究系统-热库反旋转波相互作用对热输运性质的影响。结果表明:在弱耦合情况下采用旋波近似时,稳态热流、噪声功率以及热力学不确定关系随温度单调增大。强耦合情况,反旋转波相互作用下,以上物理量呈非单调性:先增大后减小。在弱耦合情况下采用旋波近似时,热力学不确定关系与耦合强度无关。强耦合情况,反旋转波相互作用下,热力学不确定关系随着耦合强度的增大而减小,向热力学不确定关系的下限逼近。说明量子相干性有助于提高量子热机的性能,使其优于经典热机。

Spin-Peierls系统中的元激发谱

用玻色化方法和量子自洽方法研究了Spin -Peierls系统的元激发谱 ,分别计算和讨论了二聚化相的基态和单粒子激发态的能量以及阻挫对其低能行为的影响 .结果表明 ,随着阻挫的增大 ,Spin -Peierls系统中的基态能量会逐渐减小 。

Nucleon Spin Content in a Relativistic Quark Potential Model Approach

Based on a relativistic quark model approach with an effective potential , the spin content of the nucleon is investigated. Pseudo-scalar interaction between quarks and Goldstone bosons is employed to calculate the couplings between the Goldstone bosons and the nucleon. Different approaches to deal with the center of mass correction in the relativistic quark potential model approach are discussed.

Frontier Orbitals, Combustion and Redox Transfer from a Fermionic-Bosonic Orbital Perspective

Oxygenations are highly exergonic, yet combustion of organic matter is not spontaneous in an atmosphere that is 21% O2. Electrons are fermions with a quantum spin number s of 1/2ħ. An orbital containing a single electron with s = 1/2 is fermionic. Orbitals can contain a maximum of two electrons with antiparallel spins, i.e., spin magnetic quantum numbers ms of 1/2 and -1/2. An orbital filled by an electron couple has s = 0 and bosonic character. The multiplicity of a reactant is defined as |2(S)| + 1 where S is the total spin quantum number. The Wigner spin conservation rules state that multiplicity is conserved. The transmission coefficient κ of absolute reaction rate theory also indicates the necessity for spin conservation. Burning is fermionic combustion that occurs when sufficient energy is applied to a bosonic molecule to cause homolytic bond cleavage yielding fermionic products capable of reaction with the bifermionic frontier orbitals of triplet multiplicity O2. Neutrophil leucocytes kill microorganisms by bosonic combustion and employ two mechanisms for changing the multiplicity of O2 from triplet to singlet. Microorganisms, composed of bosonic singlet multiplicity molecules, do not directly react with bifermionic O2, but are highly susceptible to electrophilic attack by bosonic electronically excited singlet molecular oxygen (1O2*). Hydride ion (H-) transfer is the common mode of cytoplasmic redox metabolism. Bosonic transfer of an orbital electron couple protects from damage by obviating fermionic reaction with bifermionic O2. Bosonic coupled electron transfer raises the consideration that quantum tunneling might be involved in facilitating such redox transfer.

The Origins of Bosons and Fermions

This paper proposes that all Bosons and all Fermions originate from even more elementary constituents, which called Spin Angular Momentum Vacuum (SAMV). SAMV is filled with Primitive Spin Particles (PSP). The total square spin angular momentum of each PSP is negative, less than zero. Those PSP labeled by index ?of Casimir Operator, are called Vacuum Spin Particle (VSP), which could be contracted into so-called Vacuum Bubbles (VB). VB are identical bubbles, are 'sub-observable physical quantities'. VB are paired up into Vacuum Bubble Pair VBP. VSP ωj(or ω+,ω-) results from Self-identical vacuum bubble interaction ?through the zero order Phase Transition PT. When the 1st, 2nd, 3rd,... order PT of VBP occur, ?then VBP turn into Bosons and Fermions, excited out of sea level of SAMV ocean.

Schwinger-boson approach to anisotropy ferrimagnetic chain with bond alternation

We use the Schwinger-boson approach to study the anisotropy ferrimagnetic spin-（1/2,1） chain with bond alternation.Based on the effect of bond alternation δ,we obtain energy gap,free energy,and specific heat,respectively.The specific heat with larger bond alternation（δ 〉 0.7） displays a peak at low temperature.Based on the effect of XXZ anisotropy parameter Δ,we present excited spectrums,free energy,and specific heat,respectively.

Out-of-Equilibrium Dissipative <i>ac</i>—Susceptibility in Quantum Ising Spin Glass

The imaginary part of the non-equilibrium magnetic susceptibility of Ising spin glass in a transverse field under time-dependent longitudinal external magnetic field has been calculated at very low temperature on the basis of quantum droplet model and quantum linear response theory. Quantum and aging effects on the low temperature dynamics of the model are discussed. A comparison with recent theoretical and experimental data in spin glass is made.

Shell Model Investigation of High Spin States for Ce Isotopes

-A truncated shell model approach is presented for studying the properties oflow-lying states as well as the high-spin states in even-even nuclei with the help of thegeneralized boson-fermion expansion technique.The primary fermion state space isspanned by the interacting valence protons and neutrons with effective nucleon-nucleonforce.The truncated model space is considered as a direct sum of two subspaces corre-sponding to the configurations of（sd）N and（sd）N-1,respectively,plus a broken fermionpair.Numerical calculations are carried out for 130～134Ce isotopes.The calculated spec-trum reproduces the experimental data quite well,especially the backbending appearingin these nuclei.The results suggest that the approach is able to describe the spectroscopyof states with angular momenta up to J≈20.

Fractional Topological Insulators—A Bosonization Approach

A metallic disk with strong spin orbit interaction is investigated. The finite disk geometry introduces a confining potential. Due to the strong spin-orbit interaction and confining potential the metal disk is described by an effective one-dimensional model with a harmonic potential. The harmonic potential gives rise to classical turning points. As a result, open boundary conditions must be used. We bosonize the model and obtain chiral Bosons for each spin on the edge of the disk. When the filling fraction is reduced to the electron-electron interactions are studied by using the Jordan Wigner phase for composite fermions which give rise to a Luttinger liquid. When the metallic disk is in the proximity with a superconductor, a Fractional Topological Insulator is obtained. An experimental realization is proposed. We show that by tunning the chemical potential we control the classical turning points for which a Fractional Topological Insulator is realized.

新的规范玻色子和直线对撞机上顶夸克对产生的自旋修正

在非对角基下,研究了3-3-1模型所预言的中性规范玻色子Z′对顶夸克对产生的自旋相关过程的修正.结果表明Z′的改变可以对t↑t^-↓和t↓t^-↑散射截面产生主要修正,而且在非对角基下散射截面在相同自旋态下是不为零的.因此我们希望,Z′对顶夸克对产生的自旋结构的贡献可以在未来的ILC实验上探测到,并且可以区别不同的3-3-1模型.

原子核相互作用玻色子模型中的若干问题

在原子核的代数模型中，讨论了集体回弯效应，较高自旋的Ｆ旋混和对称态。