Effects of disorder on the blockade voltage of two-dimensional quantum dot arrays

The influence of both geometric and offset charge disorder of two-dimensional quantum dot arrays ~also known as network tunnel junctions! on their Coulomb blockade voltage Vb is studied using extensive Monte–Carlo simulations. A general increase of Vb with increasing disorder is confirmed, but an exception to the rule is found for intermediate degrees of offset charge disorder. Detailed studies of the Vb distribution reveal a stability of its minimal value against geometric disorder, whereas this figure is considerably increased for high offset charge disorder. Implications of our results for single electron device design are discussed. © 1998 American Institute of Physics. @S0021-8979~98!05022-1#