Electron transport in quantum dot chains: Dimensionality effects and hopping conductance

Detailed experimental and theoretical studies of lateral electron transport in a system of quantum dot chains demonstrate the complicated character of the conductance within the chain structure due to the interaction of conduction channels with different dimensionalities. The one-dimensional character of states in the wetting layer results in an anisotropic mobility, while the presence of the zero-dimensional states of the quantum dots leads to enhanced hopping conductance, which affects the low-temperature mobility and demonstrates an anisotropy in the conductance. These phenomena were probed by considering a one-dimensional model of hopping along with band filling effects. Differences between the model and the experimental results indicate that this system does not obey the simple one-dimensional Mott\u27s law of hopping and deserves further experimental and theoretical considerations

Wave propagation in 2D elastic composites with partially debonded fibres by the null field appraoch

Time-harmonic plane wave propagation in a two-dimensional (2D) elastic matrix with partially debonded elastic fibres of nonclassical cross-section is investigated. The modified null field approach, taking into account the asymptotic behaviour of the solution at the interface crack-tips, is exploited to obtain the numerical results for a single scatterer. The effective medium approach based on Foldy\u27s approximation is applied to estimate the average dynamic parameters of the composites containing randomly distributed partially debonded fibres of dilute concentration. Numerical results concern the longitudinal wave dispersion and attenuation owing to scattering by both randomly oriented and aligned fibres. The effects of the fibre shape, debonding (interface crack) size and direction of wave incidence on the effective P-wave velocity and attenuation coefficient are analysed

Scattering of a SH-wave by an elastic fiber of nonclassical cross section with an interface crack

The problem of interaction of a plane time-harmonic SH-wave with an elastic fiber of quasi-square or quasi-triangular cross section, when an interface crack is present between an infinite elastic matrix and the fiber, is considered. The modified null-field method taking into account the asymptotic behavior of the solution at crack tips is exploited for obtaining numerical results. The effects of fiber shape, fiber/matrix material combination, debonding (crack size), and direction of wave incidence on the scattering amplitude in the far field are analyzed