Effect of interdiffusion on electronic states in one-layer quantum ring superlattice

The effect of interdiffusion on band structure and Bloch amplitudes of two dimensional superlattice composed of initially cylindrical quantum rings is investigated in the framework of adiabatic approach and using transformation to in-plane momentum space. It is shown that the adiabatic approximation is applicable even if the ring’s height is equal to its radius, because of weak localization of electron in the superlattice plane comparing with the localization in perpendicular direction. The consideration of the dependence of effective mass on spatial coordinate and time leads to the energy correction up to 10 meV. It is shown that energy minibands rise and become wider due to interdiffusion and the dependence of Bloch amplitudes on quasimomentum direction is more pronounced in the case of diffused potential profile.     

The physics of quantum gravity

Quantum gravity is still very mysterious and far from being well understood. In this text we review the motivations for the quantification of gravity, and some expected physical consequences. We discuss the remarkable relations between scattering processes in quantum gravity and in Yang–Mills theory, and the role of string theory as a unifying theory.     

Self-switching of a transverse plane wave propagating through a two-component elastic composite

The paper discusses the results of theoretical and numerical analysis of the interaction of nonlinear elastic plane harmonic waves in a composite material whose nonlinear properties are described by modeling it with a two-phase mixture. The interaction of two transverse vertically polarized harmonic waves is studied using the method of slowly varying amplitudes. The truncated and evolutionary equations as well as the Manley-Rowe relations are derived. The mechanism of energy pumping from a strong pumping wave with frequency ω to a weak signal wave with frequency 3ω is analyzed. The switching mechanism for hypersonic waves in a nonlinear elastic composite is similar to the switching mechanism observed in transistors __________ Translated from Prikladnaya Mekhanika, Vol. 43, No. 7, pp. 35–46, July 2007.     

Kinematic cusps: Determining the missing particle mass at colliders

In many extensions of the SM, neutral massive stable particles (dark matter candidates) are produced at colliders in pairs due to an exact symmetry called a “parity”. These particles escape detection, rendering their mass measurement difficult. In the pair production of such particles via a specific (“antler”) decay topology, kinematic cusp structures are present in the invariant mass and angular distributions of the observable particles. Together with the end-points, such cusps can be used to measure the missing particle mass and the intermediate particle mass in the decay chain. Our simulation of a benchmark scenario in a Z^′$Z^{\prime }$ supersymmetric model shows that the cusp feature survives under the consideration of detector simulation and the standard model backgrounds. This technique for determining missing particle masses should be invaluable in the search for new physics at the LHC and future lepton colliders.     

Color-kinematics duality for Sudakov form factor in non-supersymmetric pure Yang–Mills theory

We study the duality between color and kinematics for the Sudakov form factors of $mathrm{tr}({F}^{2})$ in non-supersymmetric pure Yang-Mills theory. We construct the integrands that manifest the color-kinematics duality up to two loops. The resulting numerators are given in terms of Lorentz products of momenta and polarization vectors, which have the same powers of loop momenta as that from the Feynman rules. The integrands are checked by d-dimensional unitarity cuts and are valid in any dimension. We find that massless-bubble and tadpole topologies are needed at two loops to realize the color-kinematics duality. Interestingly, the two-loop solution contains a large number of free parameters suggesting the duality may hold at higher loop orders.     

Hidden analytic relations for two-loop Higgs amplitudes in QCD

We compute the Higgs plus two-quark and one-gluon amplitudes(H→qqg) and Higgs plus three-gluon amplitudes(H→3 g) in the Higgs effective theory with a general class of operators.By changing the quadratic Casimir CF to CA,the maximally transcendental parts of the H→ qqg amplitudes turn out to be equivalent to that of the H→3 g amplitudes,which also coincide with the counterparts in N=4 SYM.This generalizes the so-called maximal transcendentality principle to the Higgs amplitudes with external quark states,thus the full QCD theory.We further verify that the correspondence applies also to two-loop form factors of more general operators,in both QCD and scalar-YM theory.Another interesting relation is also observed between the planar H→qqg amplitudes and the minimal density form factors in N=4 SYM.     

Thermodynamics of coupled reactions by the method of dynamic titration: the Nickel(II)-salicylate ion system

Amplitudes of chemical relaxation signals can provide useful information as to the thermodynamics of coupled chemical reactions. The temperature-jump technique has been used to investigate the thermodynamic behavior of the Nickel(II)-3,5-dinitrosalicylate system in buffer solution, where complex formation steps are coupled to proton transfer steps. The analysis of the relaxation curves is based on the transformation of a set of coupled elementary reactions into a set of uncoupled normal reactions. By analogy with classical titrations, the experiments have been performed by changing the metal ion concentration at constant ligand concentration and pH. Each measured amplitude is associated in this way to a point of a dynamic titration and a procedure is formulated by which the values of the equilibrium constants and enthalpies of the normal reactions are simultaneously obtained by simple linear plots. From the dependence of these parameters on suitable functions of the concentrations of the reactants the values of G° and H° of the individual steps are derived. It is shown that the addition of a buffer (instead of an indicator) influences the stoichiometric coefficients of the normal reaction in such a way that measurable amplitudes are produced in systems that, as the presently investigated, in unbuffered solution would remain insensitive to the external perturbation. The circumstances under which the dynamic method offers advantages over the classical techniques are discussed.     

Optimizing formulation of hybrid model for thin and moderately thick plates

A 20 — DOF hybrid stress element based upon Mindlin plate theory is developed using the optimization design method for thin and moderately thick plates. Numerical tests consist of the convergency and performance to the plates with arbitrary thickness and shape and of the ultimate thin plate problems.Projects Supported by the National Natural Science Foundation of China.     

Is the thermodynamic behavior of the noble fluids consistent with the principle of corresponding states?

The applicability of the Principle of Corresponding States (PCS) for the noble fluids is discussed. We give the thermodynamic evidence for the dimerization of the liquid phase in heavy noble gases like argon, krypton etc. which manifests itself in deviations from the PCS. The behavior of the diameter of the entropy and the density is analyzed. It is shown that these characteristics are very sensitive to the dimerization process which takes place in the liquid phase of heavy noble gases.     

Mittlere Schwingungsamplituden und thermodynamische Funktionen von SeOF4

Mean amplitudes of vibration and thermodynamic functions for SeOF₄ have been calculated in a wide temperature range, from recently reported spectroscopic data. The results are briefly discussed and some comparisons with related species are made.