QCA Based Efficient Toffoli Gate Design and Implementation for Nanotechnology Applications

Abstract—The construct of computing is the field of ever improving and advancing systems and architectures. One of the emerging archetype that has made its ground as a research area is the concept of reversible logic in computing. Reversible logic suggests the systems with zero heat dissipation since the computational models in this logic incorporate the concept of reversibility at a ground level thereby satisfying the work and heat relations according to the laws of physics. In this paper we have first of all presented a detailed insight about the reversible logic and the perspectives related to it. Further the design of reversible logic circuits using the new emerging nanotechnology called Quantum-dot Cellular Automata (QCA) has been envisaged. These two paradigms together hold the potential of realizing ultralow power systems and architectures. In this paper, the most common and popular reversible gate called as the Toffoli Gate has been considered and designed using this new QCA technology. This paper presents the approach of using cell to cell interaction in designing the reversible circuits which result in efficient implementations. The necessary comparisons with the literature are drawn and it is explicitly shown that the proposed designs are highly optimized as compared to existing counterparts. Keyword Cellular Automata, Clocking, Invertibility, Nanotechnology, QCA, Reversibility