Shot noise in mesoscopic systems

This is a review of shot noise, the time-dependent fluctuations in the electrical current due to the discreteness of the electron charge, in small conductors. The shot-noise power can be smaller than that of a Poisson process as a result of correlations in the electron transmission imposed by the Pauli principle. This suppression takes on simple universal values in a symmetric double-barrier junction (suppression factor 1/2), a disordered metal (factor 1/3), and a chaotic cavity (factor 1/4). Loss of phase coherence has no effect on this shot-noise suppression, while thermalization of the electrons due to electron-electron scattering increases the shot noise slightly. Sub-Poissonian shot noise has been observed experimentally. So far unobserved phenomena involve the interplay of shot noise with the Aharonov-Bohm effect, Andreev reflection, and the fractional quantum Hall effect.Comment: 37 pages, Latex, 10 figures (eps). To be published in "Mesoscopic Electron Transport," edited by L. P. Kouwenhoven, G. Schoen, and L. L. Sohn, NATO ASI Series E (Kluwer Academic Publishing, Dordrecht

Electrical properties and radiation hardness of SOI systems with multilayer buried dielectric

In this work SOI structures with buried SiO2-Si3N4-SiO2 layers have been fabricated by the ZMR-technique with the aim of improving the total dose radiation hardness of the. buried dielectric layer, To optimize the fabrication process, buried layers were investigated by secondary ion mass spectrometry before and after the ZMR process, and the obtained results were compared with electrical measurements, It is shown that optimization of the preparation processes of the initial buried dielectric layers provides ZMR SOI structures with multilayer buried isolation, which are of high quality for both Si film interfaces, Particular attention is paid to the investigation of radiation-induced charge:trapping in buried insulators, Buried isolation structures with a nitride layer exhibit significant reduction of radiation-induced positive charge as compared to classical buried SiO2 layers produced by either the ZMR of the SIMOX technique

A survey of recent results in finite-source retrial queues with collisions

The aim of the present paper is to give a review of recent results on single server finite-source retrial queuing systems with collision of the customers. There are investigations when the server is reliable and there are models when the server is subject to random breakdowns and repairs depending on whether it is idle or busy. Tool supported, numerical, simulation and asymptotic methods are considered under the condition of unlimited growing number of sources. Several cases and examples are treated and the results of different approaches are compared to each other showing the advantages and disadvantages of the given method. In general we could prove that the steady-state distribution of the number of customers in the service facility can be approximated by a normal distribution with given mean and variance. Using asymptotic methods under certain conditions in steady-state the distribution of the sojourn time in the orbit and in the system can be approximated by a generalized exponential one. Furthermore, it is proved that the distribution of the number of retrials until the successful service in the limit is geometrically distributed. By the help of stochastic simulation several systems are analyzed showing directions for further analytic investigations. Tables and Figures are collected to illustrate some special features of these systems