Effects of the spin–orbit coupling on the vacancy-induced magnetism on the honeycomb lattice

The local magnetism induced by vacancies in the presence of the spin–orbit interaction is investigated based on the half-filled Kane–Mele–Hubbard model on the honeycomb lattice. Using a self-consistent mean-field theory, we find that the spin–orbit coupling will enhance the localization of the spin moments near a single vacancy. We further study the magnetic structures along the zigzag edges formed by a chain of vacancies. We find that the spin–orbit coupling tends to suppress the counter-polarized ferrimagnetic order on the upper and lower edges, because of the open of the spin–orbit gap. As a result, in the case of the balance number of sublattices, it will suppress completely this kind of ferrimagnetic order. But, for the imbalance case, a ferrimagnetic order along both edges exists because additional zero modes will not be affected by the spin–orbit coupling.     

Note on the Constraint on Modified Energy-Momentum Relation

Quantum gravity can modify the usual energy-momentum dispersion relation. We provide evidence for the argument that the modified dispersion relation is constrained by the black hole thermodynamics, for consistency of quantum gravity.     

Analysis of the Zeeman effect on D_α spectra on the EAST tokamak

Based on the passive spectroscopy,the D_α atomic emission spectra in the boundary region of the plasma have been measured by a high resolution optical spectroscopic multichannel analysis(OSMA) system in EAST tokamak.The Zeeman splitting of the D_α spectral lines has been observed.A fitting procedure by using a nonlinear least squares method was applied to fit and analyze all polarization π and ±σ components of the D_α atomic spectra to acquire the information of the local plasma.The spectral line shape was investigated according to emission spectra from different regions(e.g.,low-field side and high-field side) along the viewing chords.Each polarization component was fitted and classified into three energy categories(the cold,warm,and hot components) based on different atomic production processes,in consistent with the transition energy distribution by calculating the gradient of the D_α spectral profile.The emission position,magnetic field intensity,and flow velocity of a deuterium atom were also discussed in the context.     

Studies on the Plasma Shielding of 1.06μm Laser on the Aluminum Target

ＳｔｕｄｉｅｓｏｎｔｈｅＰｌａｓｍａＳｈｉｅｌｄｉｎｇｏｆ１．０６μｍＬａｓｅｒｏｎｔｈｅＡｌｕｍｉｎｕｍＴａｒｇｅｔＬＵＪｉａｎ；ＮＩＸｉａｏｗｕ；ＨＥＡｎｚｈｉ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＰｈｙｓｉｃｓ，ＮａｎｊｉｎｇｏｆＳｃｉｅｎｃ...     

Influence of final-state interaction on incoherent pion photoproduction on the deuteron in the region of the Δ-resonance

The influence of final-state NN and πN rescattering in incoherent pion photoproduction on the deuteron has been investigated. For the elementary photoproduction operator an effective Lagrangian model is used which describes well the elementary reaction. The interactions in the final two-body subsystems are taken in separable form. While NN rescattering shows quite a significant effect, particularly strong for neutral pion production, πN rescattering is almost negligible. Inclusion of such effects leads to an improved and quite satisfactory agreement with experiment. Received: 12 August 2002 / Accepted: 11 September 2002 / Published online: 17 January 2003 RID="a" ID="a"Present address: Physics Department, Faculty of Science, South Valley University, Sohag, Egypt. RID="b" ID="b"e-mail: arenhoev@kph.uni-mainz.de Communicated by V. Vento     

Empirical Study on the Volatility of the Hang-Seng Index

We study the statistical properties of volatility of price fluctuation for the Hang-Seng index in the Hong Kong stock market, they are measured by locally averaging over a time window T, the absolute value of price change over a short time interval Δt. The data include minute-by-minute records of the Hang-Seng index from 3 January 1994 to 28 May 1997. We find that the cumulative distribution of the volatility is consistent with the asymptotic power-law behaviour, characterized by the power exponent μ= 2.12 ± 0.04, different from that found in the previous studies as μ≈3. The volatility distribution remains the same asymptotic power-law behaviour for the time scales from T = 10 rain to T - 80 rain. Furthermore, we investigate the volatility correlations by using the power spectrum analysis and detrended fluctuation analysis. Both the methods show a long-range power-law decay with the exponent α=0.636±0.002.     

Observations on the Wilson fermions in the ϵ regime

We make several observations concerning the low quark mass region with Wilson fermions and how this is connected with the ? regime in the continuum. A transition from tiny cutoff effects to rather large discretization errors would take place in general with Wilson fermions if we lower the quark mass at finite lattice spacing. We argue that these two regions exhibit rather different behaviours concerning the coupling between cutoff effects and zero-modes. We interpolate between these two regimes adding to the continuum ? regime formulae, in the spirit of the Symanzik expansion, the relevant operators parametrising the leading cutoff effects. We compute the partition function, the chiral condensate, scalar and pseudo-scalar correlation functions. The final formulae can be used to fit lattice data to extract physical low energy constants, and to estimate systematic uncertainties coming from discretization errors. Moreover they suggest ways on how to remove these cutoff effects, the core of which are captured by the continuum zero modes.     

Study on the Level Monitoring System for the Ship-carriage-box

ＳｔｕｄｙｏｎｔｈｅＬｅｖｅｌＭｏｎｉｔｏｒｉｎｇＳｙｓｔｅｍｆｏｒｔｈｅＳｈｉｐｃａｒｉａｇｅｂｏｘＷＡＮＧＢａｏｇｕａｎｇ（ＴｉａｎｊｉｎＵｎｉｖｅｒｓｉｔｙ，Ｔｉａｎｊｉｎ３０００７２，Ｃｈｉｎａ）ＧＥＮＧＳｈｉｊｕｎ（ＨｅｂｅｉＩｎｄｕｓ...     

Research on the Penetration Characteristic of Supersonic Molecule Beam on the HL-1M Tokamak

In the HL-1M plasma experiments, two refueling ways, the pellet injection and the gas puffing, are usually used. In recent years, a new refueling method, the supersonic molecule beam (SMB) injection, has been developed. SMB injection is an attempt to enhance the penetration depth and the fuelling efficiency of gas, as well as to reduce surface absorption of the injected particles and the impurity content in the plasma. In SMB injection experiments, the gas is injected into the plasma through a Laval nozzle at high gas pressure. In this case, the peak density and improving confinement have been achieved as in the case of a pellet injection.     

Coherent π Electroproduction on the Deuteron

A general analysis of polarization phenomena for coherent pion electroproduction on deuterons is presented. The spin and isospin structures of the γ*+d→d+P⁰ amplitudes (where γ* is a virtual photon) are established and relationships between meson electroproduction on deuterons and on nucleons are given in the framework of the impulse approximation. The reaction e+d→e+d+π⁰ is investigated in detail, for a relatively large value of momentum transfer, 0.5 GeV²≤−k²≤2 GeV², both at threshold and in the region of Δ-isobar excitation. Special attention is devoted to the sensitivity of different contributions to the exclusive cross section for d(e, eπ⁰)d, as the γ*πω form factor or the NN-potential. The predicted k²-dependence of the cross section agrees well with the available experimental data.     

A Search on the Klein-Gordon Equation

The s-wave Klein-Gordon equation for the bound states is separated in two parts to see clearly the relativistic contributions to the solution in the non-relativistic limit. The reliability of the model is discussed with two examples chosen specifically.     

Quantum analysis on the four-photon interference

We present a theory for quantum interference of four photons generated by spontaneous parametric downconversion. Detailed investigation of the dependence of fourfold coincidence count rate on time delay between the incident and the reflective pump laser pulses is carried out. Gaussian type dependence is found, and good agreement between our theoretical results and experimental data reported in the literature is achieved.     

A Lower Bound on the Entanglement in the Jaynes-Cummings Model

The entanglement between an atom and field is investigated by using the 3aynes-Cummings model. The initial atomic state is supposed in a mixed state and the field is in a squeezed state. The lower bound on the entanglement quantified by concurrence is calculated. It is found that the entanglement with the atom being initially in a mixed state can be larger than that with the atom being initially in a pure state. The entanglement is not a monotone function of the squeezing parameter r of the field and it achieves the maximum for certain r and then decreases with further increase of r.     

Study on the Amplitude-squared Squeezing Characteristic of the Binomial-like State

ＳｔｕｄｙｏｎｔｈｅＡｍｐｌｉｔｕｄｅ┐ｓｑｕａｒｅｄＳｑｕｅｅｚｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉｃｏｆｔｈｅＢｉｎｏｍｉａｌ┐ｌｉｋｅＳｔａｔｅＸＩＵＸｉａｏｆｅｎｇＪＩＡＮＧＺｕｏｈｏｎｇ（ＨｅｉｌｏｎｇｊｉａｎｇＵｎｉｖｅｒｉｓｔｙ，Ｈａｒｂｉ...     

Study on the Performance of the nonlinear Joint Transform Correlator

l.IntroductionJointtransformcorrelation[1]hasbeeninvestigatedwidelyinrecentyears[2~4]be-causeitsreferenceimagesandobjectimagescanbeuPdatedinreal-time[5J.Nonlinearjointtransformcorre1ationtheoretica1ana1ysis[']showsthatcomparedwiththelinearjointtransformcorrelation,non1inearjointtransformcorrelationcanproducemorehighautcacorre1ationPeakintensity,andthelargerPeaktosideloberatiothataregoodforelectronicdevicestodetectandana]yze.Onthebasisofthemodu1ationprincipleana1ysisoftheliq-uidcrysta11ightva…     

Does the planck mass run on the cosmological-horizon scale?

Einstein's theory of general relativity contains a universal value of the Planck mass. However, one may envisage that in alternative theories of gravity the effective value of the Planck mass (or Newton's constant), which quantifies the coupling of matter to metric perturbations, can run on the cosmological-horizon scale. In this Letter, we study the consequences of a glitch in the Planck mass from subhorizon to superhorizon scales. We show that current cosmological observations severely constrain this glitch to less than 1.2%.     

A review on the solution of Grad–Shafranov equation in the cylindrical coordinates based on the Chebyshev collocation technique

Equilibrium reconstruction consists of identifying, from experimental measurements, a distribution of the plasma current density that satisfies the pressure balance constraint. Numerous methods exist to solve the Grad–Shafranov equation, describing the equilibrium of plasma confined by an axisymmetric magnetic field. In this paper, we have proposed a new numerical solution to the Grad–Shafranov equation (an axisymmetric, magnetic field transformed in cylindrical coordinates solved with the Chebyshev collocation method) when the source term (current density function) on the right-hand side is linear. The Chebyshev collocation method is a method for computing highly accurate numerical solutions of differential equations. We describe a circular cross-section of the tokamak and present numerical result of magnetic surfaces on the IR-T1 tokamak and then compare the results with an analytical solution.     

Two Uniqueness Results on the Unruh Effect¶and on PCT-Symmetry

The Unruh effect and a closely related form of PCT-symmetry have been proved in general for finite-component Wightman fields by Bisognano and Wichmann. While this result incorporates most of the fields occurring in four-dimensional high energy physics, there still are field theories of interest that are not covered (e.g., low-dimensional anyon fields and infinite-component fields). From the spectrum condition, Borchers has derived a couple of commutation relations which ”almost, but only almost“ imply the Unruh effect and PCT-symmetry. We show that this result does imply Unruh effect and PCT-symmetry provided that the operators involved in Borchers' commutation relations act geometrically on a local net of observables. Received: 15 October 2000 / Accepted: 6 March 2001     

Some remarks on the Dirac–Witten operator on pseudo-Riemannian manifolds

In this paper, we get optimal lower bounds for the eigenvalues of the Dirac–Witten operator. These estimates are given in terms of the intrinsic and extrinsic curvature expressions. In the limiting case, we prove that the spacelike submanifold is Einstein if the normal bundle is flat.