Cost-efficient full adder designs in quantum-dot cellular automata

Abstract

Quantum-dot cellular automata has all the vital characteristics needed by a post-complementary metal oxide semiconductor technology. Adder is a key constituent in any digital circuit system. Several full adder designs are proposed in quantum-dot cellular automata. The different existing techniques used in quantum-dot cellular automata adders are analysed in this work and two cost-efficient full adder designs are proposed using different crossover techniques. The proposed designs have minimum cells and are faster compared to the adders in the literature. They also have the ability to be extended to realise adders of any word length. Missing cell defect analysis is done for the proposed designs and compared with the other adder designs. The designs are validated using QCADesigner.