Quantum walks: a comprehensive review

Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important result: the computational universality of both continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing Journa

Materials science aspects of stress corrosion cracking of Russian pipelines

The work describes the features of stress corrosion cracking (SCC) on Russian gas pipelines. The influence of metal parameters of pipelines on the propagation of SCC is described. The main diagnostic features of SCC used for identification of this type of fracture, the stages of crack growth and the effect of microstructural metal parameters on their propagation are described. Accounting methods for main features crack initiation and growth in order to improve the resistance of the main pipelines metal to SCC are propose