EFFECTS OF COUPLING AND NONRESONANT TUNNELING ON COULOMB-BLOCKADE OSCILLATIONS IN AN ASYMMETRIC DOUBLE DOT STRUCTURE

We report on single electron transport through an asymmetric double do t structure with well-defined dot potential profiles. As the two dots are coupled, the conductance exhibits two pronounced types of Coulomb blockade oscillations. An analysis of the small short-period oscillati ons indicates the presence of interdot interaction. When the coupling strength is reduced, the oscillations become few irregular peaks but t hey develop into periodic oscillations again as the drain voltage is i ncreased to 0.6 mV. This appearance with increasing drain voltage is w ell explained by our model which is based on the stochastic Coulomb bl ockade model and nonresonant tunneling. (C) 1997 American Institute of Physics. [S0003-6951(97)03043-X].