Electron transport in array of centered defect quantum dots

Abstract

The electronic conductance for arrays of centered defect quantum dots is modeled using the two-dimensional transfer-matrix method. The proposed model is based on the scattering formalism. In this analysis, the subject divided into two categories including: symmetric (all dots include centered defect) and asymmetric (some dots do not have centered defect) cases. In the symmetric case, we show that inserting defects introduces blueshift in conductance as well as decreasing of distance between mini-bands (conductance gap). It is shown that with increasing of defect size and defect height a large blueshift is observed and conductance gap decreases more. In the asymmetric case, according to different arrangements of defects in arrays of quantum dots, different and interesting spectral characteristics in conductance can be achieved. In the asymmetric case, due to different energy contents of quantum dots (with and without defect), the coupling between these elements introduces new rich spectral characteristic, especially new transmission peaks in the conductance. It should be mentioned that in the symmetric case and arrays without defects there is no such situation. The proposed idea in this paper opens a new insight on designing super-molecular based on array of quantum dots for given electronic conductance.