ABSTRACT
This chapter focuses on quantum cellular automata (QCA), one of the viable technologies for the implementation of future digital systems. It presents logic synthesis approaches for QCA applications based on majority gates. In addition to developing logic circuits, QCA are also used to create interconnects. Thus, large QCA digital circuit architectures can be built using simple structures such as wires, majority gates, and inverters. A standard QCA cell consists of four quantum dots which are confined by the cell boundary. The chapter presents several four-variable standard functions and their majority gate implementations. A QCA clock, comprising several distinct periodic phases, is needed for both combinational and sequential circuits. The QCA clock performs three main functions. First, the application of clock phases decides the direction of the information flow in the circuit. Second, it provides a mechanism to simultaneously propagate the information through the circuit. Third, it provides the power needed to activate the circuit.
