Fyzikální ústav Akademie věd ČR

Seminář Úterý, 19.06.2012 15:00 - 16:00

Přednášející: A. Kalvová (Oddělení teorie kondenzovaných látek, FZÚ AV ČR, v.v.i.)
Místo: Na Slovance, místnost 117
Jazyk: anglicky
Pořadatelé: Oddělení teorie kondenzovaných látek

Abstract: We consider a standard bridge nanostructure consisting of a molecular island connected with two leads by junctions. The junctions may switch on and off independently in a sudden manner and this gives rise to non-stationary electron currents across the structure. At the instant of each switching event, the evolution of electrons starts a new from the initial conditions which depend on the previous history. These initial conditions may be taken into account in two different ways, either as synchronous, taking account of the full (correlated) state at the initial time, or as diachronous, where the initial condition is transformed explicitly into the coherent coupling between the past and the future of the system with respect to the initial time. For the model of non-interacting electrons, the calculations along both routes can be performed independently, but also reduced to each other which provides an insight into the structure of correlated initial conditions. Results of calculations using non-equilibrium Green’s functions will be shown for a sequence of up to three switching processes, demonstrating the decay of initial correlations and coherence of transient currents.