Single-electron logic based on capacitively coupled double quantum dots

We propose a new single-electron logic based on a capacitively coupled double quantum dot structure. The structure could be viewed as a pair of single-gated single-electron transistors (SET) with their “islands” capacitively coupled to each other. The numerical modeling, based on an orthodox Coulomb blockade theory, shows the unique transport characteristics of the capacitively coupled system. By choosing the two gate voltages as input states and the source–drain current magnitudes as output states, specific logic functions (NAND and exclusive-NOR) can be implemented. It shows that this new logic not only inherits the advantages of the SET-based logic circuits, but also greatly reduces the element-per-function for the implementation of logic functions.