Temporal evolution of resonant transmission under telegraph noise

TL;DR

This paper investigates how telegraph noise affects the time-dependent charge and current in a quantum dot system, revealing a crossover from coherent to incoherent transport regimes and analyzing transient behaviors.

Contribution

It introduces a single-particle basis approach to analyze the impact of telegraph noise on quantum dot transport, including transient dynamics and steady-state limits.

Findings

Fast jump rates leave transport unaffected.

Slower jump rates cause a transition from single-level to multi-level transmission.

Transient oscillations decay faster with noise, disappearing under certain conditions.

Abstract

The environment of a quantum dot, which is connected to two leads, is modeled by telegraph noise, i.e. random Markovian jumps of the (spinless) electron energy on the dot between two levels. The temporal evolutions of the charge on the dot and of the currents in the leads are studied using a recently developed single-particle basis approach, which is particularly convenient for the averaging over the histories of the noise. In the steady state limit we recover the Landauer formula. At a very fast jump rate between the two levels, the noise does not affect the transport. As the jump rate decreases, the effective average transmission crosses over from the transmission through a single (average) level to an incoherent sum of the transmissions through the two levels. 13 pages, 6 figuresThe transient temporal evolution towards the steady state is dominated by the displacement current at short times, and by the Landauer current at long times. It contains oscillating terms, which decay to zero faster than for the case without noise. When the average chemical potential on the leads equals the dot's "original" energy, without the noise, the oscillations disappear completely and the transient evolution becomes independent of the noise.