Shot noise and electron counting measurements on coupled quantum dot systems

Abstract

Measuring shot noise and electron counting are both methods for accessing informationabout the dynamics of electronic transport through a system of interest. Here we applythese tools to examine electronic transport through coupled quantum dot systems. In thefirst part of the paper we show temperature dependent shot noise measurements for astrongly coupled double-quantum-dot system. We observe super-Poissonian shot noise asexpected for coherent inter-dot coupling and asymmetric lead tunnelling rates. Inthe second part we apply direct electron counting to examine a weakly coupledtriple-dot system. A quantum point contact placed near the triple dot allowsus to monitor electron hops between the dots and the leads. This allows us to,e.g., individually characterize different tunnelling rates relevant in the system.