Electron bunching in triple quantum dot interferometers

We study electron transport through a triple quantum dot in ring or interferometer configuration. In particular, we analyze the influence of a gate voltage that detunes one of the dots, such that it becomes off-resonant. In this regime, interference effects fade away, i.e., the current becomes independent of a penetrating flux. Despite the absence of interference effects, the off-resonant dot causes intriguing noise properties which we characterize by the full-counting statistics of the transported electrons. It turns out that the detuning causes strong electron bunching. Analytical results for limiting cases support this picture. A possible application is the construction of current sources with widely tunable noise properties.