Intrinsic angular momentum in HMO

ＩｎｔｒｉｎｓｉｃａｎｇｕｌａｒｍｏｍｅｎｔｕｍｉｎＨＭＯＷＡＮＧＧａｎｇ（ＰｈｙｓｉｃｓＤｅｐａｒｔｍｅｎｔ，ＵｎｉｖｅｒｓｉｔｙｏｆＥｌｅｃｔｒｏｎｉｃＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇｙｏｆＣｈｉｎａ，Ｃｈｅｎｇｄｕ６１００５４，Ｃｈｉｎａ...     

Erratum to “A simple analytical model of the angular momentum transformation in strongly focused light beams” by Aleksandr Ya. Bekshaev

The original version of the article was published in Central European Journal of Physics 8, 94–960 (2010), DOI: 10.2478/s11534-010-0011-2. Unfortunately, due to an editorial processing error the original version of this article contains mistakes in Eqs. (23) and (25). Here we display the corrected version of these equations.     

Martensitic transformation in La1−x Yb x Ag1−y In y

The structural phase transformation of La_1–x Yb _x Ag_1–y In _y has been studied on single crystals by low temperature Laue-technique. The martensitic transformation in this pseudobinary intermetallic alloy has to be characterized as a weak orthorhtombic distortion of a single I centered unit cell (c/a1.04;a/b1.006) and a collective slipping or twinning of these cells that gives a fixed orientation between the remaining cubic room temperature structure and the martensitic phase. Above room temperature exists an order-disorder transformation from the CsCl-B2 structure to an at room temperature metastable W-A2 structure. There is no dramatic change in the physical properties of this alloy by substituting La by Yb, so we may approximate our results to LaAg_1–y In _y .This paper is dedicated to Prof. Dr. S. Methfessel on the occasion of his 60^th birthday     

Resonant Raman scattering in ultrafine CdSxSe1−x colloidal particles

Vibrational spectra of ultrafine (～1.8 nm) CdS _x Se_1?x colloidal nanoparticles (NPs) are studied by resonant Raman scattering (RRS). The detected difference of the shape and spectral position of the longitudinal optical vibration band in comparison with the spectrum of slightly larger NPs (≥ 2 nm) is explained by the dominance of surface atoms as their fraction increases above 50%. The correlation of experimental results with ab initio calculated vibrational spectra and with vibration anharmonicity enhancement as the NP size decreases is discussed.     

A study on various expansions of the angular momentum projector in terms of powers ofJ +,J − andJ 0

This note contains a discussion of various expansions of the angular momentum projection operator in terms of the operatorsJ ₊,J _? andJ ₀. This gives us opportunity to rederive the famous Löwdin's shift operator formula. As a starting point the integral representation of the projector is used, which is done in a somewhat different way than that proposed by Raynal.     

Photon-photon angular correlation ine +e− collision in QED

The angular correlation of two monochromatic photons produced ine ⁺e^– collision (annihilation), defined as the average of the cosine of the angle of separation between their outgoing momenta, is studied completely in momentum space to lowest order in the fine structure constant in QED. This is done from the expression of thee ⁺e^–-momentum-spin,-polarization-averaged conditional probability density for the angular distributions of the photons, given that the process has occurred. Although the density is in general nonvanishing for less than as well as greater than/2, the angular correlation is found to be strictly negative for all energies, indicating that the photons tend to travel in opposing directions in a statistical sense. The back-to-back motion, however, is very quickly unfavored as we move to higher energies.     

Gluon multiple scattering and the transverse momentum dependence of J/ψ production in nucleus-nucleus collisions

A J/ψ meson is mainly formed by gluon fusion for 200 GeV pp collisions. In reactions with nuclei the gluons (g) scatter off other nucleons (N) before fusing to a J/ψ, which thenshows additional transverse momentum p_T. Fitting the value of the parameter σ_gN〈p²_T〉_gN to describe the gluon multiple scattering effect in proton-nucleus data, we can reproduce the p_T distribution of J/ψ production in 200 GeV/A nucleus-nucleus collisions. The origin of the p_T distribution is traced to soft gluon radiation via the Sudakov form factor.     

Inverse scattering and solitons in An − 1 affine Toda field theories II

New single soliton solutions to the affine Toda field theories are constructed, exhibiting previously unobserved topological charges. This goes some of the way in filling the weights of the fundamental representations, but nevertheless holes in the representations remain. We use the group double-cross product form of the inverse scattering method, and restrict ourselves to the rank-one solutions.     

On equations solvable by the inverse scattering method for the Schrödinger operator

The new approach to deriving nonlinear evolution equations solvable by the inverse scattering method is proposed. In particular, this approach allows one to describe all equations solvable by the inverse scattering method for the Schrödinger operator.     

Measuring the fractional orbital angular momentum of a vortex light beam by cascaded Mach–Zehnder interferometers

We design an interferometric method for measuring the fractional orbital angular momentum of a vortex light beam by cascading Mach–Zehnder interferometers. The validity of this method is verified by simulation and theoretical analysis. We demonstrate the method experimentally for two stages of cascaded Mach–Zehnder interferometers, which can measure the fractional topological charge up to two. The experimental results agree with the theoretical results well. Since fractional orbital angular momentum may have a potential application in the field of quantum information, one can utilize the method to detect them easily and precisely.     

Calculation of hadronic contribution to the anomalous magnetic momentum of muon (g − 2)μ from light by light scattering diagram in nonlocal chiral quark model

The correction to anomalous magnetic momentum muon from the light by light scattering diagram with intermediate pion is calculated in framework nonlocal chiral quark model. To fix the model parameters it is suggested to use the values of mass and two photon width of the neutral pion. The value of the correction is in region a_m ^{p0 , LbL} = (5.05 ±0.03) ×10 ^{- 10}a_\mu ^{\pi ^0 , LbL} = (5.05 \pm 0.03) \times 10^{ - 10} for different set of model parameters.     

Substrate effect on the electronic structure in GaxIn1−xAsySb1−y/GaSb and GaxIn1−xAsySb1−y/InAs

We present a theoretical study of the substrate effect on electronic structure in cubic Ga_xIn_1−xAs_ySb_1−y lattice-matched to GaSb and InAs. Our calculations are based on the empirical pseudopotential formalism within the virtual crystal approximation where the effect of disorder is taken into account. We show that the electronic band structure of the quaternary alloy Ga_xIn_1−xAs_ySb_1−y is altered by the change of substrate for the entire range of alloy compositions x. Moreover, we find that at Ga concentrations (x≤0.8), the ionicity is less important when Ga_xIn_1−xAs_ySb_1−y is lattice-matched to GaSb instead of InAs. The information will be useful for the choice of substrate in the composition range 0–1 and hence for the determination of the lattice-matching conditions for Ga_xIn_1−xAs_ySb_1−y quaternary materials.     

Explaining μ+ spin-lattice relaxation in MnF2, belowT N,by scattering function

A relation between the spin-lattice relaxation rate (1/T ₁) of positive muons and the scattering functionS ^T (q,) is derived for the antiferromagnet MnF₂. We find good agreement between previousSR measurements of 1/T ₁ and our calculation using neutron scattering measurements ofS ^T (q,).     

The laser-irradiated transformation of intrinsic and impurity defects in narrow-gap Pb1 − xSnxTe

Changes in the electrical and optical properties of the narrow-gap solid solution Pb_{1 − x}Sn_xTe (0 ⩽x⩽ 0.20) after IR laser radiation treatment were investigated. The considerable reduction (by a factor of ~10²) of hole concentration and a gain in hole mobility was established. Transformation of the EPR spectra of Mn doped PbTe was also observed.The observed changes in the properties of Pb_{1 − x}Sn_xTe single crystals are connected with the transformation of the intrinsic and impurity defect states of Pb_{1 − x}Sn_xTe and with the drop in the microinclusions enriched with metal components of Pb_{1 − x}Sn_xTe or metal impurities. The resulting thermodiffusion of the metallic atoms to the electrically active vacancies of Pb(Sn) in the Pb_{1 − x}Sn_xTe lattice explains the reduction of hole concentration and gain in mobility.     

Comparative study of Z′ searches in e+e− and e−e− scattering

We consider indirect searches for additional neutral vector bosons in e⁺e⁻ and e⁻e⁻ collisions, and compare these two linear collider modes with similar analysis procedures and assumptions. Discovery limits and resolving power are discussed in a model-independent way.     

Raman scattering study of Al/Ga interdiffusion in ion-implanted and annealed GaAsGa1−xAlxAs superlattices

The Al/Ga interdiffusion after annealing has been characterized by Raman scattering on a GaAsGa_1−xAl_xAs superlattice where different densities of damage had been initially induced by implantation of electrically inactive isoelectronic elements, ³¹P⁺, in order to eliminate the impurity charge associated effects. To probe the mixing beyond the damaged zone of the superlattice, complementary Auger and SIMS experiments have implantation induced defects proceeds from the examination of the whole set of results.