Shot noise properties of electron transportthrough an interacting multi-terminal quantum dots system

摘要

We study the correlations of tunneling currents through an interacting quantum dots (QDs) system composed of a top single QD and a bottom qubit with purely capacitive coupling within a quantum master approach. We find that the super-Poissonian current noise of the qubit near resonance, which is a signature of coherent tunneling within the transport qubit for asymmetrical contact couplings, is strongly dependent on non-equilibrium transport through the top QD with different coupling configurations. For pure-dephasing coupling, such a super-Poissonian feature is asymmetrically washed out by increasing coupling strength showing obvious qubit level position dependence with finite bias and temperature, while for orthogonal coupling we can almost symmetrically lower the double peak to a double minimum by increasing coupling strength or adjusting the ratio of the top QD contact couplings in the large bias limit, indicating the transition from coherent tunneling to sequential tunneling.