Toffoli Gate’s Universal Structure Realization using Quantum Dot Cellular Automata

To satisfy Moore’s law, transistor sizes have to be shrinked. This poses a serious threat to CMOS technology because of its oxide thickness, diffusion barrier, power dissipation, and leakage currents. These challenges have put a full stop to the further scaling possibilities of current CMOS devices, but to keep moving the Moore’s law, an alternative novel technology has come to picture-Quantum Dot Cellular Automata(QCA). One of the primary drawbacks of all nanoelectronic design methods is power dissipation. Reversible computing has become a dependable way to mitigate this issue. Reversible logic gates are the fundamental units of reversible computing. Researchers have developed many reversible logic gates. One such reversible gate that is universal in nature is the Toffoli gate, from which all fundamental logic functions have been developed. In this work, we first constructed a Toffoli gate based on QCA and then used it to create fundamental logic gates. The proposed design reduces cell count by 43.24% and latency by 33.33%. Successful simulation and verification of the circuits were achieved using the QCADesigner 2.0.3 tool.