A majority reduction technique for adder structures in quantum-dot cellular

Quantum-dot Cellular Automata (QCA) is a nanotechnology which has potential applications in future computers. In this paper, a method for reducing the number of majority gates (a QCA logic primitive) is developed to facilitate the conversion of SOP expressions of three-variable Boolean functions into QCA majority logic. Thirteen standard functions are proposed to represent all three-variable Boolean functions and the simplified majority expressions corresponding to these standard functions are presented. By applying this method, a one-bit QCA adder, with only three majority gates and two inverters, is constructed. We will show that the proposed method is very efficient and fast in deriving the simplified majority expressions in QCA design.