Design of reversible Feynman and double Feynman gates in quantum-dot cellular automata nanotechnology

Purpose This paper aims to propose the reversible Feynman and double Feynman gates using quantum-dot cellular automata (QCA) nanotechnology with minimum QCA cells and latency which minimizes the circuit area with the more energy efficiency. Design/methodology/approach The core aim of the QCA nanotechnology is to build the high-speed, energy efficient and as much smaller devices as possible. This brings a challenge for the designers to construct the designs that fulfill the requirements as demanded. This paper proposed a new exclusive-OR (XOR) gate which is then used to implement the logical operations of the reversible Feynman and double Feynman gates using QCA nanotechnology. Findings QCA designer-E has been used for the QCA designs and the simulation results. The proposed QCA designs have less latency, occupy less area and have lesser cell count as compared to the existing ones. Originality/value The latencies of the proposed gates are 0.25 which are improved by 50% as compared to the best available design as reported in the literature. The cell count in the proposed XOR gate is 11, while it is 14 in Feynman gate and 27 in double Feynman gate. The cell count for the proposed designs is minimum as compared to the best available designs.