The need to have more performing electronics devices led the researches to scale down transistors more and more. However, when very small sizes are reached, some problems arise which led to exploration of new technologies in digital electronics. Among them, the most promising one seems to be Quantum-dot Cellular Automata (QCA), an approach in which the device is not used as a current-channel switch, but as a charge container where binary information can be represented. The basic unit of QCA device is a cell composed by four dots (seen as a vessels to host the charge) and the information is encoded depending on where the charge is localized.