Narrow Results

A Kronig–Penney model with short-range correlated impurities is used to investigate the electronic transport properties of one-dimensional disordered systems simulating both superlattices, protein chains, and polymers. Physical magnitudes characterizing the electronic charge transfer are analytically the transmission coefficient and the localization length. It is shown that a set of delocalized states occurs at particular well-defined energies. The divergence of the localization length is investigated and a critical exponent 1 is found for the barrier case which differs with the results of literature. These results support the idea that the nature of the extended states depend on the typical nature of the correlation in disorder. On this basis, the conductance of disordered superlattices is investigated as well as the relative fluctuations of the transmission coefficient.

This paper generalizes Luttinger's model by introducing curvature (d²ε(k)/dk²≠0) into the kinetic energy. An exact solution for arbitrary interactions is still possible in principle, but it now requires disentangling the eigenvalue spectrum of an harmonic string of interacting boson fields at each value of q. The additional boson fields, extracted from the excitation spectrum of the Fermi sea, are self-selected according to the nature and strength of the dispersion.

In this study, in order to obtain the optimal fabricating condition, the influences of heating temperature and time on the fabrication of zinc oxide (ZnO) nanowires are clarified. During this process, the synthesis and scanning electron microscope (SEM) images of ZnO nanostructures, produced by direct heating of metallic zinc, are presented. Besides, the SEM images and X-ray diffraction (XRD) patterns of products under different conditions are compared to analyze the surface morphology and composition of products. In the final observation, the best diameters of ZnO nanowires are achieved as 60–70 nm, which can be successfully applied as a substrate in Raman measurement. The optimal temperature is 450${}^{\circ }$C, as well as the optimal time is 40–50 min.

This paper generalizes Luttinger's model by introducing curvature (d²ε(k)/dk² ≠ 0) into the kinetic energy. An exact solution for arbitrary interactions is still possible in principle, but it now requires disentangling the eigenvalue spectrum of an harmonic string of interacting boson fields at each value of q. The additional boson fields, extracted from the excitation spectrum of the Fermi sea, are self-selected according to the nature and strength of the dispersion.