Quantum Dots in Nanoelectronic Devices
This chapter examines the issues beginning with an introduction to single-electron devices, followed by an introduction to a binary computing paradigm that addresses the issues of power dissipation, and finishing with a discussion on the nature of information and the limits of binary logic. Power gain is an important requirement for any practical electronic device. Power gain allows logic elements to restore signal levels and to overcome noise in a system. A basic Quantum-Dot Cellular Automata (QCA) cell consists of several quantum dots in a square array coupled by tunnel barriers. A great limitation of QCA devices demonstrated so far is the low temperature of operation. To raise the operating temperature, the QCA cell must be made smaller. The chapter deals with a presentation of the abrupt switching of QCA systems because it is instructive to the understanding of QCA operation.