Delocalization in a double quantum dot system

We study the delocalization process in a double dot system by merging two quantum dots of different densities. The addition of each electron to the system is detected by a capacitive technique, allowing us to monitor the evolution of the addition spectrum over a very broad range of electron densities. The data indicate that delocalization can occur in different fashions depending on the merging density. While the magnetic field has no effect on the merging of two high-density dots (n greater than or equal to 2 x 10(11) cm(-2)), it dramatically affects the merging of two dots of lower density (n similar to 1-2 x 10(11) cm(-2)). (C) 2000 Published by Elsevier Science B.V. All rights reserved.