Master equation approach to transient quantum transport incorporating with initial correlations

TL;DR

This paper develops an exact master equation approach to analyze transient quantum transport in nanostructures, explicitly including initial correlations between the system and leads, revealing their impact on transport dynamics and steady-state behavior.

Contribution

It introduces a novel exact master equation that incorporates initial system-lead and lead-lead correlations for non-interacting nanostructures, advancing understanding of initial correlation effects.

Findings

Initial correlations influence transient and steady-state transport.

The master equation explicitly includes time-dependent fluctuations.

Initial correlations affect electron localization and bound states.

Abstract

In this paper, the exact transient quantum transport of non-interacting nanostructures is investigated in the presence of initial system-lead correlations and initial lead-lead correlations for a device system coupled to general electronic leads. The exact master equation incorporating with initial correlations is derived through the extended quantum Langevin equation. The effects of the initial correlations are manifested through the time-dependent fluctuations contained explicitly in the exact master equation. The transient transport current incorporating with initial correlations is obtained from the exact master equation. The resulting transient transport current can be expressed in terms of the single-particle propagating 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 so that electron localized bound states occur in the device system.