Multifunction reversbile logic gate: Logic synthesis and design implementation in QCA

Abstract

Quantum-dot Cellular Automata (QCA) is a newly developed paradigm for digital design. It explains how computation can be performed using nano sized quantum dots. One of the trending application of QCA is the design of reversible logic circuits and gates. Reversible logic is a dissipation less digital logic. According to this logic digital circuitry with almost zero power dissipation can be designed. The most important application of reversible logic is quantum computing. Quantum Computation cannot be performed without the use of reversible circuits. A number of reversible gates have been designed and used in quantum computing. The best way to derive the maximum out of reversible computation is to design those gates and circuits using systems which are inherently reversible. This is true for the quantum mechanical systems. For this quantum level designing Quantum-dot Cellular Automata stands as the appropriate choice. It's a nano level based archetype. Performing multiple functions using single circuits has always been the aim of the digital industry researchers. In reversible logic the approach is developing towards designing multifunction gates that can perform a number of functions using a same circuit with some adjustments. This development has however not yet been explored much in QCA. In this paper the majority logic equations for the outputs of a multifunction reversible logic gate are derived and the novel Quantum-dot Cellular Automata design is proposed. Some of the functions of multifunction reversible logic gate are discussed and simulated results using QCA Designer 2.0.3 are shown in the figure.