Majority-Layered T Hybridization: Implementing Reversible Logic Using Quantum-Dot Cellular Automata

Abstract

Reversible computation gains advantage over the other emerging nanotechnologies to minimize power dissipation. The implementation of the Reversible circuits using Quantum-dot Cellular Automata (QCA) has been in the point of focus after the exposure of "Atomistic QCA" which is operable at room temperature. Researchers realize the need of the proper methodology by which implementation of reversible benchmarks using QCA would be effective in spectrum of design metrics such as area requirement, delay and O-Cost. In this work, the "Majority-Layered T Hybridization Methodology" is proposed to fulfil the need. The reversible gate library consisting of CNOT, NOT, Toffoli and SWAP Gate (CNTS Gates) has been developed and simulated with the help of the functionality of the proposed methodology. Moreover, Multiple Control Toffoli Gate (MCT) is designed with the proposed Majority-Layered T Hybridization Methodology with the proper formulation of Area requirement, Delay and O-Cost. The 3 × 3 Toffoli Gate using the Majority-Layered T Hybridization shows 18.61% improvement in effective area requirement and 8.33% lesser O-Cost compared to the best reported design so far. As Reversible Benchmark circuits require generic Toffoli Gate, the proposed methodology has been verified with the 4 × 4, 5 × 5 and 6 × 6 Toffoli Gates. By analyzing the result, mathematical formulation has been developed to properly estimate the design metrics for higher order Toffoli Gates. The proposed methodology is verified by the Reversible Benchmark rd-32 circuit the QCA layout which shows lowest AUF value till date. The Majority-Layered T Hybridization and its circuit layouts are simulated, tested and verified by the QCA Designer tool.