Weak localization in bilayer graphene

We have performed the first experimental investigation of quantum interference corrections to the conductivity of a bilayer graphene structure. A negative magnetoresistance--a signature of weak localization--is observed at different carrier densities, including the electroneutrality region. It is very different, however, from the weak localization in conventional two-dimensional systems. We show that it is controlled not only by the dephasing time, but also by different elastic processes that break the effective time-reversal symmetry and provide intervalley scattering.     

The Mechanism of Isomerization Recyclization of Diacetyl Derivatives of Pyridinium Salts

A mechanism has been considered for the recyclization of pyridinium salts using their diacetyl derivatives as an example. The enthalpies of formation of the intermediates were estimated by the molecular mechanics method (MMX88). The nature of the rate-determining step of the reaction is discussed.     

Weak localization in graphene flakes

We show that the manifestation of quantum interference in graphene is very different from that in conventional two-dimensional systems. Because of the chiral nature of charge carriers, it is not only sensitive to inelastic, phase-breaking scattering, but also to a number of elastic scattering processes. We study weak localization in different samples and at different carrier densities, including the Dirac region, and find the characteristic rates that determine it. We show how the shape and quality of graphene flakes affect the values of the elastic and inelastic rates and discuss their physical origin.     

Convergence of the method of orthogonal polynomials for approximate solution of integral equations of the first kind with Π-kernels

The method of orthogonal polynomials for approxiamte solution of integral equations of the first kind with -kernels is substantiated. The solvability of the corresponding algebraic systems is proved, and estimates for the rate of the convergence of approxiamte solutions to exact ones are established. The applicability of the method of orthogonal polynomials to approximate solution of integral equations of the second kind with -kernels is shown, as well as its high effectiveness in solving integral equations of the first kind with -kernels. Concrete -kernels, most often occurring in applications, are presented.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 43, No. 2, pp. 223–229, February, 1991.