Master equation approach to transient quantum transport in nanostructures incorporating initial correlations

In this paper, the exact transient quantum transport in noninteracting nanostructures is investigated in the presence of initial correlations for a device system coupled to general electronic leads. The exact master equation incorporating initial system-lead correlations is derived through the extended quantum Langevin equation. The effects of the initial correlations are manifested in terms of the time-dependent fluctuations contained explicitly in the exact master equation. The transient electron transport incorporating initial correlations is obtained from the exact master equation. The resulting electron transport current can be expressed in terms of the single-particle propagation and correlation Green functions of the device system. We show that the initial correlations can affect quantum transport not only in the transient regime, but also in the steady-state limit when system-lead couplings are strong enough that electron localized states occur in the device system.