Sequential tunneling through an array of electrostatically coupled quantum dots

We present a master equation approach for sequential tunneling through an ensemble of small quantum dots which interact electrostatically. In the calculated current–voltage characteristics for homogeneous arrays of quantum dots the step structure disappears with increasing number of dots. On the contrary, we show for inhomogeneous ensembles of quantum dots that Coulomb blocking can lead to strong negative differential conductance, which may explain the observation of single peaks at low bias in the current–voltage characteristic in recent tunneling experiments.