Memory effects and nonequilibrium transport in open many-particle quantum systems

Considerable effort was focused on deepening the understanding of transport in mesoscopic structures, especially on short time scales. It was argued that proper treatment of relaxation mechanisms in these systems requires treating the system as open. Hence, a basis for generalization of the nonequilibrium Green's functions formalism for analysis fo open systems was introduced. Using the so-called partial-trace-free approach, the two-time correlation functions and the time-ordered single-particle Green's functions for an open system were defined.